Index: TODO
===================================================================
diff -u -r7efafd7b19c58bf0f5ac486779e8ce778e60c9bb -rf93a860bacabe371e1f01bd3f3841015c6b14a21
--- TODO	(.../TODO)	(revision 7efafd7b19c58bf0f5ac486779e8ce778e60c9bb)
+++ TODO	(.../TODO)	(revision f93a860bacabe371e1f01bd3f3841015c6b14a21)
@@ -1262,8 +1262,13 @@
 - new flag for configure: "nx::configure checkresult on|off"
 - turn off result-checking for non-converters, when checking is off
   (per default, it is on)
-- extended regression test for optional result checking
+- extended regressi
 
+- new flag for configure: "nx::configure checkarguments on|off"
+- turn off argument-checking for non-converters, when checking is off
+  (per default, it is on)
+- extended regression test for optional argument checking
+
 TODO: 
 - reflect changes in /is/objectproperty/info has/info is/ in migration guide
 - implement built-in-converter for "baseclass" and "metaclass"?
Index: generic/gentclAPI.decls
===================================================================
diff -u -r7efafd7b19c58bf0f5ac486779e8ce778e60c9bb -rf93a860bacabe371e1f01bd3f3841015c6b14a21
--- generic/gentclAPI.decls	(.../gentclAPI.decls)	(revision 7efafd7b19c58bf0f5ac486779e8ce778e60c9bb)
+++ generic/gentclAPI.decls	(.../gentclAPI.decls)	(revision f93a860bacabe371e1f01bd3f3841015c6b14a21)
@@ -32,7 +32,7 @@
 }
 
 xotclCmd configure XOTclConfigureCmd {
-  {-argName "configureoption" -required 1 -type "filter|softrecreate|objectsystems|keepinitcmd|checkresult"}
+  {-argName "configureoption" -required 1 -type "filter|softrecreate|objectsystems|keepinitcmd|checkresults|checkarguments"}
   {-argName "value" -required 0 -type tclobj}
 }
 xotclCmd createobjectsystem XOTclCreateObjectSystemCmd {
Index: generic/gentclAPI.tcl
===================================================================
diff -u -r1008a85cf8fe5d95365568f6c765a83389028ff2 -rf93a860bacabe371e1f01bd3f3841015c6b14a21
--- generic/gentclAPI.tcl	(.../gentclAPI.tcl)	(revision 1008a85cf8fe5d95365568f6c765a83389028ff2)
+++ generic/gentclAPI.tcl	(.../gentclAPI.tcl)	(revision f93a860bacabe371e1f01bd3f3841015c6b14a21)
@@ -197,7 +197,7 @@
 $intro
   if (ArgumentParse(interp, objc, objv, $obj, objv[0], 
                      method_definitions[$idx].paramDefs, 
-                     method_definitions[$idx].nrParameters, 
+                     method_definitions[$idx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -285,7 +285,8 @@
 
 static int ArgumentParse(Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[], 
                          XOTclObject *obj, Tcl_Obj *procName,
-                         XOTclParam CONST *paramPtr, int nrParameters, parseContext *pc);
+                         XOTclParam CONST *paramPtr, int nrParameters, int doCheck,
+			 parseContext *pc);
 
 static int getMatchObject(Tcl_Interp *interp, Tcl_Obj *patternObj, Tcl_Obj *origObj,
 			  XOTclObject **matchObject, CONST char **pattern);
Index: generic/tclAPI.h
===================================================================
diff -u -r7efafd7b19c58bf0f5ac486779e8ce778e60c9bb -rf93a860bacabe371e1f01bd3f3841015c6b14a21
--- generic/tclAPI.h	(.../tclAPI.h)	(revision 7efafd7b19c58bf0f5ac486779e8ce778e60c9bb)
+++ generic/tclAPI.h	(.../tclAPI.h)	(revision f93a860bacabe371e1f01bd3f3841015c6b14a21)
@@ -79,13 +79,13 @@
 static int convertToConfigureoption(Tcl_Interp *interp, Tcl_Obj *objPtr, XOTclParam CONST *pPtr, 
 			    ClientData *clientData, Tcl_Obj **outObjPtr) {
   int index, result;
-  static CONST char *opts[] = {"filter", "softrecreate", "objectsystems", "keepinitcmd", "checkresult", NULL};
+  static CONST char *opts[] = {"filter", "softrecreate", "objectsystems", "keepinitcmd", "checkresults", "checkarguments", NULL};
   result = Tcl_GetIndexFromObj(interp, objPtr, opts, "configureoption", 0, &index);
   *clientData = (ClientData) INT2PTR(index + 1);
   *outObjPtr = objPtr;
   return result;
 }
-enum ConfigureoptionIdx {ConfigureoptionNULL, ConfigureoptionFilterIdx, ConfigureoptionSoftrecreateIdx, ConfigureoptionObjectsystemsIdx, ConfigureoptionKeepinitcmdIdx, ConfigureoptionCheckresultIdx};
+enum ConfigureoptionIdx {ConfigureoptionNULL, ConfigureoptionFilterIdx, ConfigureoptionSoftrecreateIdx, ConfigureoptionObjectsystemsIdx, ConfigureoptionKeepinitcmdIdx, ConfigureoptionCheckresultsIdx, ConfigureoptionCheckargumentsIdx};
   
 static int convertToCurrentoption(Tcl_Interp *interp, Tcl_Obj *objPtr, XOTclParam CONST *pPtr, 
 			    ClientData *clientData, Tcl_Obj **outObjPtr) {
@@ -130,7 +130,8 @@
 
 static int ArgumentParse(Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[], 
                          XOTclObject *obj, Tcl_Obj *procName,
-                         XOTclParam CONST *paramPtr, int nrParameters, parseContext *pc);
+                         XOTclParam CONST *paramPtr, int nrParameters, int doCheck,
+			 parseContext *pc);
 
 static int getMatchObject(Tcl_Interp *interp, Tcl_Obj *patternObj, Tcl_Obj *origObj,
 			  XOTclObject **matchObject, CONST char **pattern);
@@ -392,7 +393,7 @@
   if (!cl) return XOTclObjErrType(interp, objv[0], "Class", "");
   if (ArgumentParse(interp, objc, objv, (XOTclObject *) cl, objv[0], 
                      method_definitions[XOTclCAllocMethodIdx].paramDefs, 
-                     method_definitions[XOTclCAllocMethodIdx].nrParameters, 
+                     method_definitions[XOTclCAllocMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -411,7 +412,7 @@
   if (!cl) return XOTclObjErrType(interp, objv[0], "Class", "");
   if (ArgumentParse(interp, objc, objv, (XOTclObject *) cl, objv[0], 
                      method_definitions[XOTclCCreateMethodIdx].paramDefs, 
-                     method_definitions[XOTclCCreateMethodIdx].nrParameters, 
+                     method_definitions[XOTclCCreateMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -430,7 +431,7 @@
   if (!cl) return XOTclObjErrType(interp, objv[0], "Class", "");
   if (ArgumentParse(interp, objc, objv, (XOTclObject *) cl, objv[0], 
                      method_definitions[XOTclCDeallocMethodIdx].paramDefs, 
-                     method_definitions[XOTclCDeallocMethodIdx].nrParameters, 
+                     method_definitions[XOTclCDeallocMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -449,7 +450,7 @@
   if (!cl) return XOTclObjErrType(interp, objv[0], "Class", "");
   if (ArgumentParse(interp, objc, objv, (XOTclObject *) cl, objv[0], 
                      method_definitions[XOTclCFilterGuardMethodIdx].paramDefs, 
-                     method_definitions[XOTclCFilterGuardMethodIdx].nrParameters, 
+                     method_definitions[XOTclCFilterGuardMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -469,7 +470,7 @@
   if (!cl) return XOTclObjErrType(interp, objv[0], "Class", "");
   if (ArgumentParse(interp, objc, objv, (XOTclObject *) cl, objv[0], 
                      method_definitions[XOTclCMixinGuardMethodIdx].paramDefs, 
-                     method_definitions[XOTclCMixinGuardMethodIdx].nrParameters, 
+                     method_definitions[XOTclCMixinGuardMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -489,7 +490,7 @@
   if (!cl) return XOTclObjErrType(interp, objv[0], "Class", "");
   if (ArgumentParse(interp, objc, objv, (XOTclObject *) cl, objv[0], 
                      method_definitions[XOTclCNewMethodIdx].paramDefs, 
-                     method_definitions[XOTclCNewMethodIdx].nrParameters, 
+                     method_definitions[XOTclCNewMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -508,7 +509,7 @@
   if (!cl) return XOTclObjErrType(interp, objv[0], "Class", "");
   if (ArgumentParse(interp, objc, objv, (XOTclObject *) cl, objv[0], 
                      method_definitions[XOTclCRecreateMethodIdx].paramDefs, 
-                     method_definitions[XOTclCRecreateMethodIdx].nrParameters, 
+                     method_definitions[XOTclCRecreateMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -527,7 +528,7 @@
   if (!cl) return XOTclObjErrType(interp, objv[0], "Class", "");
   if (ArgumentParse(interp, objc, objv, (XOTclObject *) cl, objv[0], 
                      method_definitions[XOTclClassInfoFilterguardMethodIdx].paramDefs, 
-                     method_definitions[XOTclClassInfoFilterguardMethodIdx].nrParameters, 
+                     method_definitions[XOTclClassInfoFilterguardMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -546,7 +547,7 @@
   if (!cl) return XOTclObjErrType(interp, objv[0], "Class", "");
   if (ArgumentParse(interp, objc, objv, (XOTclObject *) cl, objv[0], 
                      method_definitions[XOTclClassInfoFiltermethodsMethodIdx].paramDefs, 
-                     method_definitions[XOTclClassInfoFiltermethodsMethodIdx].nrParameters, 
+                     method_definitions[XOTclClassInfoFiltermethodsMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -566,7 +567,7 @@
   if (!cl) return XOTclObjErrType(interp, objv[0], "Class", "");
   if (ArgumentParse(interp, objc, objv, (XOTclObject *) cl, objv[0], 
                      method_definitions[XOTclClassInfoForwardMethodIdx].paramDefs, 
-                     method_definitions[XOTclClassInfoForwardMethodIdx].nrParameters, 
+                     method_definitions[XOTclClassInfoForwardMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -586,7 +587,7 @@
   if (!cl) return XOTclObjErrType(interp, objv[0], "Class", "");
   if (ArgumentParse(interp, objc, objv, (XOTclObject *) cl, objv[0], 
                      method_definitions[XOTclClassInfoHeritageMethodIdx].paramDefs, 
-                     method_definitions[XOTclClassInfoHeritageMethodIdx].nrParameters, 
+                     method_definitions[XOTclClassInfoHeritageMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -605,7 +606,7 @@
   if (!cl) return XOTclObjErrType(interp, objv[0], "Class", "");
   if (ArgumentParse(interp, objc, objv, (XOTclObject *) cl, objv[0], 
                      method_definitions[XOTclClassInfoInstancesMethodIdx].paramDefs, 
-                     method_definitions[XOTclClassInfoInstancesMethodIdx].nrParameters, 
+                     method_definitions[XOTclClassInfoInstancesMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -639,7 +640,7 @@
   if (!cl) return XOTclObjErrType(interp, objv[0], "Class", "");
   if (ArgumentParse(interp, objc, objv, (XOTclObject *) cl, objv[0], 
                      method_definitions[XOTclClassInfoMethodMethodIdx].paramDefs, 
-                     method_definitions[XOTclClassInfoMethodMethodIdx].nrParameters, 
+                     method_definitions[XOTclClassInfoMethodMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -659,7 +660,7 @@
   if (!cl) return XOTclObjErrType(interp, objv[0], "Class", "");
   if (ArgumentParse(interp, objc, objv, (XOTclObject *) cl, objv[0], 
                      method_definitions[XOTclClassInfoMethodsMethodIdx].paramDefs, 
-                     method_definitions[XOTclClassInfoMethodsMethodIdx].nrParameters, 
+                     method_definitions[XOTclClassInfoMethodsMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -682,7 +683,7 @@
   if (!cl) return XOTclObjErrType(interp, objv[0], "Class", "");
   if (ArgumentParse(interp, objc, objv, (XOTclObject *) cl, objv[0], 
                      method_definitions[XOTclClassInfoMixinOfMethodIdx].paramDefs, 
-                     method_definitions[XOTclClassInfoMixinOfMethodIdx].nrParameters, 
+                     method_definitions[XOTclClassInfoMixinOfMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -717,7 +718,7 @@
   if (!cl) return XOTclObjErrType(interp, objv[0], "Class", "");
   if (ArgumentParse(interp, objc, objv, (XOTclObject *) cl, objv[0], 
                      method_definitions[XOTclClassInfoMixinclassesMethodIdx].paramDefs, 
-                     method_definitions[XOTclClassInfoMixinclassesMethodIdx].nrParameters, 
+                     method_definitions[XOTclClassInfoMixinclassesMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -752,7 +753,7 @@
   if (!cl) return XOTclObjErrType(interp, objv[0], "Class", "");
   if (ArgumentParse(interp, objc, objv, (XOTclObject *) cl, objv[0], 
                      method_definitions[XOTclClassInfoMixinguardMethodIdx].paramDefs, 
-                     method_definitions[XOTclClassInfoMixinguardMethodIdx].nrParameters, 
+                     method_definitions[XOTclClassInfoMixinguardMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -771,7 +772,7 @@
   if (!cl) return XOTclObjErrType(interp, objv[0], "Class", "");
   if (ArgumentParse(interp, objc, objv, (XOTclObject *) cl, objv[0], 
                      method_definitions[XOTclClassInfoSlotsMethodIdx].paramDefs, 
-                     method_definitions[XOTclClassInfoSlotsMethodIdx].nrParameters, 
+                     method_definitions[XOTclClassInfoSlotsMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -790,7 +791,7 @@
   if (!cl) return XOTclObjErrType(interp, objv[0], "Class", "");
   if (ArgumentParse(interp, objc, objv, (XOTclObject *) cl, objv[0], 
                      method_definitions[XOTclClassInfoSubclassMethodIdx].paramDefs, 
-                     method_definitions[XOTclClassInfoSubclassMethodIdx].nrParameters, 
+                     method_definitions[XOTclClassInfoSubclassMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -824,7 +825,7 @@
   if (!cl) return XOTclObjErrType(interp, objv[0], "Class", "");
   if (ArgumentParse(interp, objc, objv, (XOTclObject *) cl, objv[0], 
                      method_definitions[XOTclClassInfoSuperclassMethodIdx].paramDefs, 
-                     method_definitions[XOTclClassInfoSuperclassMethodIdx].nrParameters, 
+                     method_definitions[XOTclClassInfoSuperclassMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -844,7 +845,7 @@
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object", "");
   if (ArgumentParse(interp, objc, objv, obj, objv[0], 
                      method_definitions[XOTclOAutonameMethodIdx].paramDefs, 
-                     method_definitions[XOTclOAutonameMethodIdx].nrParameters, 
+                     method_definitions[XOTclOAutonameMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -865,7 +866,7 @@
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object", "");
   if (ArgumentParse(interp, objc, objv, obj, objv[0], 
                      method_definitions[XOTclOCleanupMethodIdx].paramDefs, 
-                     method_definitions[XOTclOCleanupMethodIdx].nrParameters, 
+                     method_definitions[XOTclOCleanupMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -894,7 +895,7 @@
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object", "");
   if (ArgumentParse(interp, objc, objv, obj, objv[0], 
                      method_definitions[XOTclODestroyMethodIdx].paramDefs, 
-                     method_definitions[XOTclODestroyMethodIdx].nrParameters, 
+                     method_definitions[XOTclODestroyMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -913,7 +914,7 @@
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object", "");
   if (ArgumentParse(interp, objc, objv, obj, objv[0], 
                      method_definitions[XOTclOExistsMethodIdx].paramDefs, 
-                     method_definitions[XOTclOExistsMethodIdx].nrParameters, 
+                     method_definitions[XOTclOExistsMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -932,7 +933,7 @@
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object", "");
   if (ArgumentParse(interp, objc, objv, obj, objv[0], 
                      method_definitions[XOTclOFilterGuardMethodIdx].paramDefs, 
-                     method_definitions[XOTclOFilterGuardMethodIdx].nrParameters, 
+                     method_definitions[XOTclOFilterGuardMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -962,7 +963,7 @@
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object", "");
   if (ArgumentParse(interp, objc, objv, obj, objv[0], 
                      method_definitions[XOTclOMixinGuardMethodIdx].paramDefs, 
-                     method_definitions[XOTclOMixinGuardMethodIdx].nrParameters, 
+                     method_definitions[XOTclOMixinGuardMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -982,7 +983,7 @@
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object", "");
   if (ArgumentParse(interp, objc, objv, obj, objv[0], 
                      method_definitions[XOTclONoinitMethodIdx].paramDefs, 
-                     method_definitions[XOTclONoinitMethodIdx].nrParameters, 
+                     method_definitions[XOTclONoinitMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1001,7 +1002,7 @@
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object", "");
   if (ArgumentParse(interp, objc, objv, obj, objv[0], 
                      method_definitions[XOTclORequireNamespaceMethodIdx].paramDefs, 
-                     method_definitions[XOTclORequireNamespaceMethodIdx].nrParameters, 
+                     method_definitions[XOTclORequireNamespaceMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1050,7 +1051,7 @@
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object", "");
   if (ArgumentParse(interp, objc, objv, obj, objv[0], 
                      method_definitions[XOTclOVolatileMethodIdx].paramDefs, 
-                     method_definitions[XOTclOVolatileMethodIdx].nrParameters, 
+                     method_definitions[XOTclOVolatileMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1069,7 +1070,7 @@
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object", "");
   if (ArgumentParse(interp, objc, objv, obj, objv[0], 
                      method_definitions[XOTclOVwaitMethodIdx].paramDefs, 
-                     method_definitions[XOTclOVwaitMethodIdx].nrParameters, 
+                     method_definitions[XOTclOVwaitMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1088,7 +1089,7 @@
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object", "");
   if (ArgumentParse(interp, objc, objv, obj, objv[0], 
                      method_definitions[XOTclObjInfoCallableMethodIdx].paramDefs, 
-                     method_definitions[XOTclObjInfoCallableMethodIdx].nrParameters, 
+                     method_definitions[XOTclObjInfoCallableMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1113,7 +1114,7 @@
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object", "");
   if (ArgumentParse(interp, objc, objv, obj, objv[0], 
                      method_definitions[XOTclObjInfoChildrenMethodIdx].paramDefs, 
-                     method_definitions[XOTclObjInfoChildrenMethodIdx].nrParameters, 
+                     method_definitions[XOTclObjInfoChildrenMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1132,7 +1133,7 @@
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object", "");
   if (ArgumentParse(interp, objc, objv, obj, objv[0], 
                      method_definitions[XOTclObjInfoClassMethodIdx].paramDefs, 
-                     method_definitions[XOTclObjInfoClassMethodIdx].nrParameters, 
+                     method_definitions[XOTclObjInfoClassMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1151,7 +1152,7 @@
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object", "");
   if (ArgumentParse(interp, objc, objv, obj, objv[0], 
                      method_definitions[XOTclObjInfoFilterguardMethodIdx].paramDefs, 
-                     method_definitions[XOTclObjInfoFilterguardMethodIdx].nrParameters, 
+                     method_definitions[XOTclObjInfoFilterguardMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1170,7 +1171,7 @@
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object", "");
   if (ArgumentParse(interp, objc, objv, obj, objv[0], 
                      method_definitions[XOTclObjInfoFiltermethodsMethodIdx].paramDefs, 
-                     method_definitions[XOTclObjInfoFiltermethodsMethodIdx].nrParameters, 
+                     method_definitions[XOTclObjInfoFiltermethodsMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1191,7 +1192,7 @@
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object", "");
   if (ArgumentParse(interp, objc, objv, obj, objv[0], 
                      method_definitions[XOTclObjInfoForwardMethodIdx].paramDefs, 
-                     method_definitions[XOTclObjInfoForwardMethodIdx].nrParameters, 
+                     method_definitions[XOTclObjInfoForwardMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1211,7 +1212,7 @@
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object", "");
   if (ArgumentParse(interp, objc, objv, obj, objv[0], 
                      method_definitions[XOTclObjInfoHasMixinMethodIdx].paramDefs, 
-                     method_definitions[XOTclObjInfoHasMixinMethodIdx].nrParameters, 
+                     method_definitions[XOTclObjInfoHasMixinMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1230,7 +1231,7 @@
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object", "");
   if (ArgumentParse(interp, objc, objv, obj, objv[0], 
                      method_definitions[XOTclObjInfoHasTypeMethodIdx].paramDefs, 
-                     method_definitions[XOTclObjInfoHasTypeMethodIdx].nrParameters, 
+                     method_definitions[XOTclObjInfoHasTypeMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1249,7 +1250,7 @@
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object", "");
   if (ArgumentParse(interp, objc, objv, obj, objv[0], 
                      method_definitions[XOTclObjInfoHasnamespaceMethodIdx].paramDefs, 
-                     method_definitions[XOTclObjInfoHasnamespaceMethodIdx].nrParameters, 
+                     method_definitions[XOTclObjInfoHasnamespaceMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1268,7 +1269,7 @@
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object", "");
   if (ArgumentParse(interp, objc, objv, obj, objv[0], 
                      method_definitions[XOTclObjInfoIsMethodIdx].paramDefs, 
-                     method_definitions[XOTclObjInfoIsMethodIdx].nrParameters, 
+                     method_definitions[XOTclObjInfoIsMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1287,7 +1288,7 @@
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object", "");
   if (ArgumentParse(interp, objc, objv, obj, objv[0], 
                      method_definitions[XOTclObjInfoMethodMethodIdx].paramDefs, 
-                     method_definitions[XOTclObjInfoMethodMethodIdx].nrParameters, 
+                     method_definitions[XOTclObjInfoMethodMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1307,7 +1308,7 @@
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object", "");
   if (ArgumentParse(interp, objc, objv, obj, objv[0], 
                      method_definitions[XOTclObjInfoMethodsMethodIdx].paramDefs, 
-                     method_definitions[XOTclObjInfoMethodsMethodIdx].nrParameters, 
+                     method_definitions[XOTclObjInfoMethodsMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1330,7 +1331,7 @@
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object", "");
   if (ArgumentParse(interp, objc, objv, obj, objv[0], 
                      method_definitions[XOTclObjInfoMixinclassesMethodIdx].paramDefs, 
-                     method_definitions[XOTclObjInfoMixinclassesMethodIdx].nrParameters, 
+                     method_definitions[XOTclObjInfoMixinclassesMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1365,7 +1366,7 @@
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object", "");
   if (ArgumentParse(interp, objc, objv, obj, objv[0], 
                      method_definitions[XOTclObjInfoMixinguardMethodIdx].paramDefs, 
-                     method_definitions[XOTclObjInfoMixinguardMethodIdx].nrParameters, 
+                     method_definitions[XOTclObjInfoMixinguardMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1384,7 +1385,7 @@
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object", "");
   if (ArgumentParse(interp, objc, objv, obj, objv[0], 
                      method_definitions[XOTclObjInfoParentMethodIdx].paramDefs, 
-                     method_definitions[XOTclObjInfoParentMethodIdx].nrParameters, 
+                     method_definitions[XOTclObjInfoParentMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1403,7 +1404,7 @@
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object", "");
   if (ArgumentParse(interp, objc, objv, obj, objv[0], 
                      method_definitions[XOTclObjInfoPrecedenceMethodIdx].paramDefs, 
-                     method_definitions[XOTclObjInfoPrecedenceMethodIdx].nrParameters, 
+                     method_definitions[XOTclObjInfoPrecedenceMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1423,7 +1424,7 @@
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object", "");
   if (ArgumentParse(interp, objc, objv, obj, objv[0], 
                      method_definitions[XOTclObjInfoSlotObjectsMethodIdx].paramDefs, 
-                     method_definitions[XOTclObjInfoSlotObjectsMethodIdx].nrParameters, 
+                     method_definitions[XOTclObjInfoSlotObjectsMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1442,7 +1443,7 @@
   if (!obj) return XOTclObjErrType(interp, objv[0], "Object", "");
   if (ArgumentParse(interp, objc, objv, obj, objv[0], 
                      method_definitions[XOTclObjInfoVarsMethodIdx].paramDefs, 
-                     method_definitions[XOTclObjInfoVarsMethodIdx].nrParameters, 
+                     method_definitions[XOTclObjInfoVarsMethodIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1460,7 +1461,7 @@
 
   if (ArgumentParse(interp, objc, objv, NULL, objv[0], 
                      method_definitions[XOTclAliasCmdIdx].paramDefs, 
-                     method_definitions[XOTclAliasCmdIdx].nrParameters, 
+                     method_definitions[XOTclAliasCmdIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1483,7 +1484,7 @@
 
   if (ArgumentParse(interp, objc, objv, NULL, objv[0], 
                      method_definitions[XOTclAssertionCmdIdx].paramDefs, 
-                     method_definitions[XOTclAssertionCmdIdx].nrParameters, 
+                     method_definitions[XOTclAssertionCmdIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1512,7 +1513,7 @@
 
   if (ArgumentParse(interp, objc, objv, NULL, objv[0], 
                      method_definitions[XOTclConfigureCmdIdx].paramDefs, 
-                     method_definitions[XOTclConfigureCmdIdx].nrParameters, 
+                     method_definitions[XOTclConfigureCmdIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1531,7 +1532,7 @@
 
   if (ArgumentParse(interp, objc, objv, NULL, objv[0], 
                      method_definitions[XOTclCreateObjectSystemCmdIdx].paramDefs, 
-                     method_definitions[XOTclCreateObjectSystemCmdIdx].nrParameters, 
+                     method_definitions[XOTclCreateObjectSystemCmdIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1551,7 +1552,7 @@
 
   if (ArgumentParse(interp, objc, objv, NULL, objv[0], 
                      method_definitions[XOTclCurrentCmdIdx].paramDefs, 
-                     method_definitions[XOTclCurrentCmdIdx].nrParameters, 
+                     method_definitions[XOTclCurrentCmdIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1569,7 +1570,7 @@
 
   if (ArgumentParse(interp, objc, objv, NULL, objv[0], 
                      method_definitions[XOTclDeprecatedCmdIdx].paramDefs, 
-                     method_definitions[XOTclDeprecatedCmdIdx].nrParameters, 
+                     method_definitions[XOTclDeprecatedCmdIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1589,7 +1590,7 @@
 
   if (ArgumentParse(interp, objc, objv, NULL, objv[0], 
                      method_definitions[XOTclDispatchCmdIdx].paramDefs, 
-                     method_definitions[XOTclDispatchCmdIdx].nrParameters, 
+                     method_definitions[XOTclDispatchCmdIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1609,7 +1610,7 @@
 
   if (ArgumentParse(interp, objc, objv, NULL, objv[0], 
                      method_definitions[XOTclExistsVarCmdIdx].paramDefs, 
-                     method_definitions[XOTclExistsVarCmdIdx].nrParameters, 
+                     method_definitions[XOTclExistsVarCmdIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1628,7 +1629,7 @@
 
   if (ArgumentParse(interp, objc, objv, NULL, objv[0], 
                      method_definitions[XOTclFinalizeObjCmdIdx].paramDefs, 
-                     method_definitions[XOTclFinalizeObjCmdIdx].nrParameters, 
+                     method_definitions[XOTclFinalizeObjCmdIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1646,7 +1647,7 @@
 
   if (ArgumentParse(interp, objc, objv, NULL, objv[0], 
                      method_definitions[XOTclForwardCmdIdx].paramDefs, 
-                     method_definitions[XOTclForwardCmdIdx].nrParameters, 
+                     method_definitions[XOTclForwardCmdIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1673,7 +1674,7 @@
 
   if (ArgumentParse(interp, objc, objv, NULL, objv[0], 
                      method_definitions[XOTclImportvarCmdIdx].paramDefs, 
-                     method_definitions[XOTclImportvarCmdIdx].nrParameters, 
+                     method_definitions[XOTclImportvarCmdIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1691,7 +1692,7 @@
 
   if (ArgumentParse(interp, objc, objv, NULL, objv[0], 
                      method_definitions[XOTclInterpObjCmdIdx].paramDefs, 
-                     method_definitions[XOTclInterpObjCmdIdx].nrParameters, 
+                     method_definitions[XOTclInterpObjCmdIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1709,7 +1710,7 @@
 
   if (ArgumentParse(interp, objc, objv, NULL, objv[0], 
                      method_definitions[XOTclInvalidateObjectParameterCmdIdx].paramDefs, 
-                     method_definitions[XOTclInvalidateObjectParameterCmdIdx].nrParameters, 
+                     method_definitions[XOTclInvalidateObjectParameterCmdIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1727,7 +1728,7 @@
 
   if (ArgumentParse(interp, objc, objv, NULL, objv[0], 
                      method_definitions[XOTclIsCmdIdx].paramDefs, 
-                     method_definitions[XOTclIsCmdIdx].nrParameters, 
+                     method_definitions[XOTclIsCmdIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1747,7 +1748,7 @@
 
   if (ArgumentParse(interp, objc, objv, NULL, objv[0], 
                      method_definitions[XOTclIsObjectCmdIdx].paramDefs, 
-                     method_definitions[XOTclIsObjectCmdIdx].nrParameters, 
+                     method_definitions[XOTclIsObjectCmdIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1765,7 +1766,7 @@
 
   if (ArgumentParse(interp, objc, objv, NULL, objv[0], 
                      method_definitions[XOTclMethodCmdIdx].paramDefs, 
-                     method_definitions[XOTclMethodCmdIdx].nrParameters, 
+                     method_definitions[XOTclMethodCmdIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1791,7 +1792,7 @@
 
   if (ArgumentParse(interp, objc, objv, NULL, objv[0], 
                      method_definitions[XOTclMethodPropertyCmdIdx].paramDefs, 
-                     method_definitions[XOTclMethodPropertyCmdIdx].nrParameters, 
+                     method_definitions[XOTclMethodPropertyCmdIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1813,7 +1814,7 @@
 
   if (ArgumentParse(interp, objc, objv, NULL, objv[0], 
                      method_definitions[XOTclMyCmdIdx].paramDefs, 
-                     method_definitions[XOTclMyCmdIdx].nrParameters, 
+                     method_definitions[XOTclMyCmdIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1832,7 +1833,7 @@
 
   if (ArgumentParse(interp, objc, objv, NULL, objv[0], 
                      method_definitions[XOTclNSCopyCmdsIdx].paramDefs, 
-                     method_definitions[XOTclNSCopyCmdsIdx].nrParameters, 
+                     method_definitions[XOTclNSCopyCmdsIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1851,7 +1852,7 @@
 
   if (ArgumentParse(interp, objc, objv, NULL, objv[0], 
                      method_definitions[XOTclNSCopyVarsIdx].paramDefs, 
-                     method_definitions[XOTclNSCopyVarsIdx].nrParameters, 
+                     method_definitions[XOTclNSCopyVarsIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1870,7 +1871,7 @@
 
   if (ArgumentParse(interp, objc, objv, NULL, objv[0], 
                      method_definitions[XOTclQualifyObjCmdIdx].paramDefs, 
-                     method_definitions[XOTclQualifyObjCmdIdx].nrParameters, 
+                     method_definitions[XOTclQualifyObjCmdIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1888,7 +1889,7 @@
 
   if (ArgumentParse(interp, objc, objv, NULL, objv[0], 
                      method_definitions[XOTclRelationCmdIdx].paramDefs, 
-                     method_definitions[XOTclRelationCmdIdx].nrParameters, 
+                     method_definitions[XOTclRelationCmdIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1908,7 +1909,7 @@
 
   if (ArgumentParse(interp, objc, objv, NULL, objv[0], 
                      method_definitions[XOTclSetVarCmdIdx].paramDefs, 
-                     method_definitions[XOTclSetVarCmdIdx].nrParameters, 
+                     method_definitions[XOTclSetVarCmdIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
@@ -1928,7 +1929,7 @@
 
   if (ArgumentParse(interp, objc, objv, NULL, objv[0], 
                      method_definitions[XOTclSetterCmdIdx].paramDefs, 
-                     method_definitions[XOTclSetterCmdIdx].nrParameters, 
+                     method_definitions[XOTclSetterCmdIdx].nrParameters, 1,
                      &pc) != TCL_OK) {
     return TCL_ERROR;
   } else {
Index: generic/xotcl.c
===================================================================
diff -u -r7efafd7b19c58bf0f5ac486779e8ce778e60c9bb -rf93a860bacabe371e1f01bd3f3841015c6b14a21
--- generic/xotcl.c	(.../xotcl.c)	(revision 7efafd7b19c58bf0f5ac486779e8ce778e60c9bb)
+++ generic/xotcl.c	(.../xotcl.c)	(revision f93a860bacabe371e1f01bd3f3841015c6b14a21)
@@ -216,8 +216,8 @@
 static int ProcessMethodArguments(parseContext *pcPtr, Tcl_Interp *interp,
                                   XOTclObject *object, int pushFrame, XOTclParamDefs *paramDefs,
                                   CONST char *methodName, int objc, Tcl_Obj *CONST objv[]);
-static int ArgumentCheck(Tcl_Interp *interp, Tcl_Obj *objPtr, struct XOTclParam CONST *pPtr, int *flags,
-                         ClientData *clientData, Tcl_Obj **outObjPtr);
+static int ArgumentCheck(Tcl_Interp *interp, Tcl_Obj *objPtr, struct XOTclParam CONST *pPtr, int doCheck,
+			 int *flags, ClientData *clientData, Tcl_Obj **outObjPtr);
 static int Parametercheck(Tcl_Interp *interp, Tcl_Obj *objPtr, Tcl_Obj *valueObj, 
 			  const char *varNamePrefix, int doCheck, XOTclParam **paramPtrPtr);
 
@@ -5173,11 +5173,10 @@
   int overflow, limit = 60, nameLen;
   const char *procName;
 
-  /*fprintf(stderr, "MakeProcError zzzz %p type %p refCount %d\n", 
+  /*fprintf(stderr, "MakeProcError %p type %p refCount %d\n", 
     procNameObj, procNameObj->typePtr, procNameObj->refCount);*/
 
   procName = Tcl_GetStringFromObj(procNameObj, &nameLen);
-  /*fprintf(stderr, ".... procName = %s\n", procName);*/
   overflow = (nameLen > limit);
   Tcl_AppendObjToErrorInfo(interp, Tcl_ObjPrintf(
 						 "\n    (procedure \"%.*s%s\" line %d)",
@@ -5520,6 +5519,7 @@
   CONST char *methodName = data[2];
   XOTclObject *object = cscPtr->self;
   XOTclObjectOpt *opt = object->opt;
+  XOTclParamDefs *paramDefs;
   int rc;
 
   /*fprintf(stderr, "---- FinalizeProcMethod result %d, csc %p, pcPtr %p, obj %p\n",
@@ -5532,16 +5532,15 @@
           );
 # endif
 
-  { XOTclParamDefs *paramDefs = ParamDefsGet(cscPtr->cmdPtr);
+  paramDefs = ParamDefsGet(cscPtr->cmdPtr);
 
-    if (result == TCL_OK && paramDefs && paramDefs->returns) {
-      Tcl_Obj *valueObj = Tcl_GetObjResult(interp);
-      /*fprintf(stderr, "***** we have returns for method '%s' check %s, value %p\n", 
-	methodName, ObjStr(paramDefs->returns), valueObj);*/
-      result = Parametercheck(interp, paramDefs->returns, valueObj, "return-value:", 
-			      RUNTIME_STATE(interp)->doCheckresult,
-			      NULL);
-    }
+  if (result == TCL_OK && paramDefs && paramDefs->returns) {
+    Tcl_Obj *valueObj = Tcl_GetObjResult(interp);
+    /*fprintf(stderr, "***** we have returns for method '%s' check %s, value %p\n", 
+      methodName, ObjStr(paramDefs->returns), valueObj);*/
+    result = Parametercheck(interp, paramDefs->returns, valueObj, "return-value:", 
+			    RUNTIME_STATE(interp)->doCheckResults,
+			    NULL);
   }
 
   if (opt && object->teardown && (opt->checkoptions & CHECK_POST)) {
@@ -5745,7 +5744,7 @@
     /*fprintf(stderr, "***** we have returns for method '%s' check %s, value %p is shared %d\n", 
       methodName, ObjStr(paramDefs->returns), valueObj, Tcl_IsShared(valueObj));*/
     result = Parametercheck(interp, paramDefs->returns, valueObj, "return-value:", 
-			    RUNTIME_STATE(interp)->doCheckresult,
+			    RUNTIME_STATE(interp)->doCheckResults,
 			    NULL);
   }
 
@@ -5834,7 +5833,7 @@
       /* fprintf(stderr, "***** CMD we have returns for method '%s' check %s, value %p\n", 
 	 methodName, ObjStr(paramDefs->returns), valueObj);*/
       result = Parametercheck(interp, paramDefs->returns, valueObj, "return-value:", 
-			      RUNTIME_STATE(interp)->doCheckresult,
+			      RUNTIME_STATE(interp)->doCheckResults,
 			      NULL);
     }
   }
@@ -5858,12 +5857,14 @@
 # define MethodDispatch __MethodDispatch__
 #endif
 
+#if 0
 static Tcl_Obj*
 SubcmdObj(Tcl_Interp *interp, CONST char *start, size_t len) {
   Tcl_Obj *checker = Tcl_NewStringObj("sub=", 4);
   Tcl_AppendLimitedToObj(checker, start, len, INT_MAX, NULL);
   return checker;
 }
+#endif
 
 static int
 DispatchUnknownMethod(ClientData clientData, 
@@ -8993,7 +8994,9 @@
     int result, flags = 0;
     ClientData checkedData;
 
-    result = ArgumentCheck(interp, objv[1], cd->paramsPtr, &flags, &checkedData, &outObjPtr);
+    result = ArgumentCheck(interp, objv[1], cd->paramsPtr, 
+			   RUNTIME_STATE(interp)->doCheckArguments,
+			   &flags, &checkedData, &outObjPtr);
 
     if (result == TCL_OK) {
       result = setInstVar(interp, object, objv[0], outObjPtr);
@@ -9715,10 +9718,18 @@
 }
 
 static int
-ArgumentCheck(Tcl_Interp *interp, Tcl_Obj *objPtr, struct XOTclParam CONST *pPtr, int *flags,
-	      ClientData *clientData, Tcl_Obj **outObjPtr) {
+ArgumentCheck(Tcl_Interp *interp, Tcl_Obj *objPtr, struct XOTclParam CONST *pPtr, int doCheck,
+	      int *flags, ClientData *clientData, Tcl_Obj **outObjPtr) {
   int result;
 
+  if (doCheck == 0 && (pPtr->flags & (XOTCL_ARG_IS_CONVERTER|XOTCL_ARG_INITCMD)) == 0) {
+    /*fprintf(stderr, "*** omit  argument check for arg %s flags %.6x\n",pPtr->name, pPtr->flags);*/
+    *outObjPtr = objPtr;
+    *clientData = ObjStr(objPtr);
+    *flags = 0;
+    return TCL_OK;
+  }
+
   if (pPtr->flags & XOTCL_ARG_MULTIVALUED) {
     int objc, i;
     Tcl_Obj **ov;
@@ -9756,8 +9767,8 @@
              switch to the version of this handler building an output
              list 
           */
-          fprintf(stderr, "switch to output list construction for value %s\n",
-		  ObjStr(elementObjPtr));
+          /*fprintf(stderr, "switch to output list construction for value %s\n",
+	    ObjStr(elementObjPtr));*/
           *flags |= XOTCL_PC_MUST_DECR;
           result = ArgumentCheckHelper(interp, objPtr, pPtr, flags, clientData, outObjPtr);
           break;
@@ -9837,7 +9848,9 @@
         /* Check the default value, unless we have an INITCMD or METHOD */
         if ((pPtr->flags & (XOTCL_ARG_INITCMD|XOTCL_ARG_METHOD)) == 0) {
           int mustDecrList = 0;
-          if (ArgumentCheck(interp, newValue, pPtr, &mustDecrList, &checkedData, &pcPtr->objv[i]) != TCL_OK) {
+          if (ArgumentCheck(interp, newValue, pPtr, 
+			    RUNTIME_STATE(interp)->doCheckArguments,
+			    &mustDecrList, &checkedData, &pcPtr->objv[i]) != TCL_OK) {
             return TCL_ERROR;
           }
           
@@ -9881,7 +9894,7 @@
 static int
 ArgumentParse(Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[],
               XOTclObject *object, Tcl_Obj *procNameObj,
-              XOTclParam CONST *paramPtr, int nrParams,
+              XOTclParam CONST *paramPtr, int nrParams, int doCheck,
               parseContext *pcPtr) {
   int i, o, flagCount, nrReq = 0, nrOpt = 0, dashdash = 0, nrDashdash = 0;
   XOTclParam CONST *pPtr;
@@ -9938,8 +9951,8 @@
                           i, nppPtr->name, ObjStr(objv[p]), nppPtr->nrArgs,
                           nppPtr->flags & XOTCL_ARG_REQUIRED ? "req":"not req", nppPtr->converter);
 #endif
-                  if (ArgumentCheck(interp, objv[p], nppPtr, &pcPtr->flags[j],
-				    &pcPtr->clientData[j], &pcPtr->objv[j]) != TCL_OK) {
+                  if (ArgumentCheck(interp, objv[p], nppPtr, doCheck,
+				    &pcPtr->flags[j], &pcPtr->clientData[j], &pcPtr->objv[j]) != TCL_OK) {
                     return TCL_ERROR;
                   }
 
@@ -9996,7 +10009,9 @@
       /*fprintf(stderr, "... arg %s req %d converter %p try to set on %d: '%s' convertViaCmd %p\n",
               pPtr->name, pPtr->flags & XOTCL_ARG_REQUIRED, pPtr->converter, i, ObjStr(objv[o]), 
               convertViaCmd);*/
-      if (ArgumentCheck(interp, objv[o], pPtr, &pcPtr->flags[i], &pcPtr->clientData[i], &pcPtr->objv[i]) != TCL_OK) {
+
+      if (ArgumentCheck(interp, objv[o], pPtr, doCheck,
+			&pcPtr->flags[i], &pcPtr->clientData[i], &pcPtr->objv[i]) != TCL_OK) {
         return TCL_ERROR;
       }
       if (pcPtr->flags[i] & XOTCL_PC_MUST_DECR) 
@@ -11153,13 +11168,19 @@
       RUNTIME_STATE(interp)->doKeepinitcmd = bool;
     break;
 
-  case ConfigureoptionCheckresultIdx:
+  case ConfigureoptionCheckresultsIdx:
     Tcl_SetBooleanObj(Tcl_GetObjResult(interp),
-                      (RUNTIME_STATE(interp)->doCheckresult));
+                      (RUNTIME_STATE(interp)->doCheckResults));
     if (valueObj)
-      RUNTIME_STATE(interp)->doCheckresult = bool;
+      RUNTIME_STATE(interp)->doCheckResults = bool;
     break;
 
+  case ConfigureoptionCheckargumentsIdx:
+    Tcl_SetBooleanObj(Tcl_GetObjResult(interp),
+                      (RUNTIME_STATE(interp)->doCheckArguments));
+    if (valueObj)
+      RUNTIME_STATE(interp)->doCheckArguments = bool;
+    break;
   }
   return TCL_OK;
 }
@@ -12741,18 +12762,13 @@
   paramPtr = paramWrapperPtr->paramPtr;
   if (paramPtrPtr) *paramPtrPtr = paramPtr;
 
-  if (paramPtr->flags & XOTCL_ARG_IS_CONVERTER) {
-    /* always call checker if it is a converter */
-    doCheck = 1;
-  }
-
-  if (!doCheck) {
+  /*  if (!doCheck) {
     outObjPtr = valueObj;
     checkedData = ObjStr(valueObj);
     return TCL_OK;
-  }
+    }*/
 
-  result = ArgumentCheck(interp, valueObj, paramPtr, &flags, &checkedData, &outObjPtr);
+  result = ArgumentCheck(interp, valueObj, paramPtr, doCheck, &flags, &checkedData, &outObjPtr);
 
   /*fprintf(stderr, "ParamSetFromAny paramPtr %p final refcount of wrapper %d can free %d\n",
     paramPtr, paramWrapperPtr->refCount,  paramWrapperPtr->canFree);*/
@@ -14580,7 +14596,9 @@
   }
 
   result = ArgumentParse(interp, objc, objv, object, objv[0],
-                         paramDefs->paramsPtr, paramDefs->nrParams, pcPtr);
+                         paramDefs->paramsPtr, paramDefs->nrParams, 
+			 RUNTIME_STATE(interp)->doCheckArguments,
+			 pcPtr);
   if (object && pushFrame) {
     XOTcl_PopFrameObj(interp, framePtr);
   }
@@ -15047,7 +15065,8 @@
 #endif
 
   RUNTIME_STATE(interp)->doFilters = 1;
-  RUNTIME_STATE(interp)->doCheckresult = 1;
+  RUNTIME_STATE(interp)->doCheckResults = 1;
+  RUNTIME_STATE(interp)->doCheckArguments = 1;
 
   /* create xotcl namespace */
   RUNTIME_STATE(interp)->XOTclNS =
Index: generic/xotclInt.h
===================================================================
diff -u -r7efafd7b19c58bf0f5ac486779e8ce778e60c9bb -rf93a860bacabe371e1f01bd3f3841015c6b14a21
--- generic/xotclInt.h	(.../xotclInt.h)	(revision 7efafd7b19c58bf0f5ac486779e8ce778e60c9bb)
+++ generic/xotclInt.h	(.../xotclInt.h)	(revision f93a860bacabe371e1f01bd3f3841015c6b14a21)
@@ -664,8 +664,8 @@
   int doFilters;
   int doSoftrecreate;
   int doKeepinitcmd;
-  int doCheckresult;
-  int doCheckparameter;
+  int doCheckResults;
+  int doCheckArguments;
   int exitHandlerDestroyRound;
   int returnCode;
   int overloadedMethods;
Index: library/lib/test.tcl
===================================================================
diff -u -r18122dd21b99cf0d5b4cd01635048641a23aa051 -rf93a860bacabe371e1f01bd3f3841015c6b14a21
--- library/lib/test.tcl	(.../test.tcl)	(revision 18122dd21b99cf0d5b4cd01635048641a23aa051)
+++ library/lib/test.tcl	(.../test.tcl)	(revision f93a860bacabe371e1f01bd3f3841015c6b14a21)
@@ -43,7 +43,7 @@
       # from global evals. So, this approach is not suitable for all test
       # (but for most).
       #
-      # Current limitations: just for xotcl2, no method/mixin cleanup/var cleanup
+      # Current limitations: just for nx::Objects, no method/mixin cleanup/var cleanup
       #
       set :case $name
       if {[info exists arg]} {
@@ -73,9 +73,9 @@
       set testfile [file rootname [file tail [info script]]]
       if {[info exists :case]} {
 	if {![info exists :ccount(${:case})]} {set :ccount(${:case}) 0}
-	set :name $testfile-${:case}.[format %.3d [incr :ccount(${:case})]]
+	set :name $testfile/${:case}.[format %.3d [incr :ccount(${:case})]]
       } else {
-	set :name $testfile-t.[format %.3d [incr :count]]
+	set :name $testfile/t.[format %.3d [incr :count]]
       }
       :create ${:name} -name ${:name} {*}$args
     }
Index: tests/parameters.tcl
===================================================================
diff -u -r7efafd7b19c58bf0f5ac486779e8ce778e60c9bb -rf93a860bacabe371e1f01bd3f3841015c6b14a21
--- tests/parameters.tcl	(.../parameters.tcl)	(revision 7efafd7b19c58bf0f5ac486779e8ce778e60c9bb)
+++ tests/parameters.tcl	(.../parameters.tcl)	(revision f93a860bacabe371e1f01bd3f3841015c6b14a21)
@@ -92,6 +92,10 @@
   #? {::nsf::is object o -type C} 0
   #? {::nsf::is object o -hasmixin C} 0
 
+  # scripted checker
+  ? {::nsf::is metaclass ::nx::Class} 1
+  ? {::nsf::is metaclass ::nx::Object} 0
+
   ? {::nsf::is -complain class o1} {expected class but got "o1" for parameter value}
   ? {::nsf::is class o1} 0
   ? {::nsf::is -complain class Test} 1
@@ -1111,6 +1115,75 @@
   ? {c1 b 101} {::c1: unable to dispatch method 'b'}
   ? {c1 c 102} {::c1: unable to dispatch method 'c'}
 }
+
+Test parameter count 10000
+Test case check-arguments {
+
+  Class create Foo {
+    :method noarg {} {return ""} 
+    :method onearg {x} {return $x} 
+    :method intarg {x:integer} {return $x} 
+    :method intsarg {x:integer,multivalued} {return $x} 
+    :method boolarg {x:boolean} {return $x} 
+    :method classarg {x:class} {return $x} 
+    :method upperarg {x:upper} {return $x} 
+    :method metaclassarg {x:metaclass} {return $x} 
+    :create f1
+  }
+  
+  ? {f1 noarg} ""
+  ? {f1 onearg 1} 1
+  # built-in checker
+  ? {f1 intarg 1} 1
+  ? {f1 intarg a} {expected integer but got "a" for parameter x}
+  ? {f1 intsarg {10 11 12}} {10 11 12}
+  ? {f1 intsarg {10 11 1a2}} {invalid value in "10 11 1a2": expected integer but got "1a2" for parameter x}
+  ? {f1 boolarg 1} 1
+  ? {f1 boolarg a} {expected boolean value but got "a" for parameter x}
+  ? {f1 classarg ::Foo} ::Foo
+  ? {f1 classarg f1} {expected class but got "f1" for parameter x}
+  # tcl checker
+  ? {f1 upperarg ABC} ABC
+  ? {f1 upperarg abc} {expected upper but got "abc" for parameter x}
+  # scripted  checker
+  ? {f1 metaclassarg ::nx::Class} ::nx::Class
+  ? {f1 metaclassarg ::Foo} {expected metaclass but got "::Foo" for parameter x}
+}
+
+::nsf::configure checkarguments off
+Test case check-arguments-nocheck {
+
+  Class create Foo {
+    :method noarg {} {return ""} 
+    :method onearg {x} {return $x} 
+    :method intarg {x:integer} {return $x} 
+    :method intsarg {x:integer,multivalued} {return $x} 
+    :method boolarg {x:boolean} {return $x} 
+    :method classarg {x:class} {return $x} 
+    :method upperarg {x:upper} {return $x} 
+    :method metaclassarg {x:metaclass} {return $x} 
+    :create f1
+  }
+  
+  ? {f1 noarg} ""
+  ? {f1 onearg 1} 1
+  # built-in checker
+  ? {f1 intarg 1} 1
+  ? {f1 intarg a} a
+  ? {f1 intsarg {10 11 12}} {10 11 12}
+  ? {f1 intsarg {10 11 1a2}} {10 11 1a2}
+  ? {f1 boolarg 1} 1
+  ? {f1 boolarg a} a
+  ? {f1 classarg ::Foo} ::Foo
+  ? {f1 classarg f1} f1
+  # tcl checker
+  ? {f1 upperarg ABC} ABC
+  ? {f1 upperarg abc} abc
+  # scripted  checker
+  ? {f1 metaclassarg ::nx::Class} ::nx::Class
+  ? {f1 metaclassarg ::Foo} ::Foo
+}
+
 ## TODO regression test for type checking, parameter options (initcmd,
 ## substdefault, combinations with defaults, ...), etc.
 
Index: tests/returns.tcl
===================================================================
diff -u -r7efafd7b19c58bf0f5ac486779e8ce778e60c9bb -rf93a860bacabe371e1f01bd3f3841015c6b14a21
--- tests/returns.tcl	(.../returns.tcl)	(revision 7efafd7b19c58bf0f5ac486779e8ce778e60c9bb)
+++ tests/returns.tcl	(.../returns.tcl)	(revision f93a860bacabe371e1f01bd3f3841015c6b14a21)
@@ -9,7 +9,7 @@
 #
 ::nsf::configure checkresult true
 
-Test parameter count 10
+Test parameter count 10000
 Test case int-returns { 
     nx::Class create C {
 	# scripted method without paramdefs
@@ -34,7 +34,7 @@
     ? {c1 bar-nok 1 2} {expected integer but got "a" for parameter return-value}
 
     ? {c1 incr x} 1
-    ? {c1 incr x} 12
+    ? {c1 incr x} 10002
 
     ? {c1 lappend l e1} {expected integer but got "e1" for parameter return-value}
 
@@ -43,8 +43,14 @@
 
     # reset it to emtpy
     ? {::nsf::methodproperty C lappend returns ""} ""
+    ? {::nsf::methodproperty C bar-ok1 returns ""} ""
+    ? {::nsf::methodproperty C bar-ok2 returns ""} ""
+    ? {::nsf::methodproperty C bar-nok returns ""} ""
 
-    # no checking on lappend
+    # no checking 
+    ? {c1 bar-ok1 1 2} 1
+    ? {c1 bar-ok2 1 2} 1
+    ? {c1 bar-nok 1 2} a
     ? {c1 lappend l e2} "e1 e2"
 
     # query returns "", if there is no returns checking
@@ -53,6 +59,7 @@
 
 }
 
+Test parameter count 10
 Test case app-specific-returns { 
 
     ::nx::methodParameterSlot method type=range {name value arg} {
@@ -88,6 +95,7 @@
     ? {c1 lappend l e1} {Value 'e1' of parameter return-value not between 1 and 30}
 }
 
+Test parameter count 1000
 Test case converting-returns { 
 
     ::nx::methodParameterSlot method type=sex {name value args} {
@@ -141,9 +149,9 @@
 #
 # turn off result checking
 #
-::nsf::configure checkresult false
+::nsf::configure checkresults false
 
-Test parameter count 10
+Test parameter count 10000
 Test case int-returns-nocheck { 
     nx::Class create C {
 	# scripted method without paramdefs
@@ -168,7 +176,7 @@
     ? {c1 bar-nok 1 2} a
 
     ? {c1 incr x} 1
-    ? {c1 incr x} 12
+    ? {c1 incr x} 10002
 
     ? {c1 lappend l e1} e1
 
@@ -188,6 +196,7 @@
 
 }
 
+Test parameter count 10
 Test case app-specific-returns-nocheck { 
 
     ::nx::methodParameterSlot method type=range {name value arg} {
@@ -223,6 +232,7 @@
     ? {c1 lappend l e1} e1
 }
 
+Test parameter count 1000
 Test case converting-returns-nocheck { 
 
     ::nx::methodParameterSlot method type=sex {name value args} {