Index: generic/nsf.c
===================================================================
diff -u -r70d242f602e1807f7ef67cf9d642bb78f059be44 -r5678f49b80ef65fdcfad0d2500f0c06eb1e5e320
--- generic/nsf.c	(.../nsf.c)	(revision 70d242f602e1807f7ef67cf9d642bb78f059be44)
+++ generic/nsf.c	(.../nsf.c)	(revision 5678f49b80ef65fdcfad0d2500f0c06eb1e5e320)
@@ -98,6 +98,7 @@
 
 typedef struct SetterCmdClientData {
   NsfObject *object;
+  Tcl_Obj *varNameObj;
   NsfParam *paramsPtr;
 } SetterCmdClientData;
 
@@ -10544,7 +10545,7 @@
 			   &flags, &checkedData, &outObjPtr);
 
     if (result == TCL_OK) {
-      result = SetInstVar(interp, object, objv[0], outObjPtr);
+      result = SetInstVar(interp, object, cd->varNameObj, outObjPtr);
 
       if (flags & NSF_PC_MUST_DECR) {
         DECR_REF_COUNT(outObjPtr);
@@ -10553,7 +10554,7 @@
     return result;
 
   } else {
-    return SetInstVar(interp, object, objv[0], objc == 2 ? objv[1] : NULL);
+    return SetInstVar(interp, object, cd->varNameObj, objc == 2 ? objv[1] : NULL);
   }
 }
 
@@ -11027,6 +11028,10 @@
 SetterCmdDeleteProc(ClientData clientData) {
   SetterCmdClientData *setterClientData = (SetterCmdClientData *)clientData;
 
+  if (setterClientData->varNameObj) {  
+      DECR_REF_COUNT(setterClientData->varNameObj);
+  }
+
   if (setterClientData->paramsPtr) {
     ParamsFree(setterClientData->paramsPtr);
   }
@@ -14396,6 +14401,8 @@
 
   setterClientData = NEW(SetterCmdClientData);
   setterClientData->paramsPtr = NULL;
+  setterClientData->varNameObj = NULL;
+
   length = strlen(methodName);
 
   for (j=0; j<length; j++) {
@@ -14416,10 +14423,14 @@
       return result;
     }
     methodName = setterClientData->paramsPtr->name;
+    setterClientData->varNameObj = Tcl_NewStringObj(methodName,-1);
   } else {
     setterClientData->paramsPtr = NULL;
+    setterClientData->varNameObj = parameter;
   }
 
+  INCR_REF_COUNT(setterClientData->varNameObj);
+
   if (cl) {
     result = NsfAddClassMethod(interp, (Nsf_Class *)cl, methodName,
                                  (Tcl_ObjCmdProc*)NsfSetterMethod,
Index: tests/parameters.test
===================================================================
diff -u -r5357e15dadb6bbb59394222187096850742f8c3b -r5678f49b80ef65fdcfad0d2500f0c06eb1e5e320
--- tests/parameters.test	(.../parameters.test)	(revision 5357e15dadb6bbb59394222187096850742f8c3b)
+++ tests/parameters.test	(.../parameters.test)	(revision 5678f49b80ef65fdcfad0d2500f0c06eb1e5e320)
@@ -1335,3 +1335,45 @@
   # ... and check, it did not reset the value to the default
   ? {c1 a} 2
 }
+
+Test case setter-under-coloncmd-and-interpvarresolver {
+  # There are (at least) three forms of object-namespace alignment in
+  # NSF:
+  # 1. Same-named namespace (::omon) predates a same-named object
+  # (::omon), the namespace is registered as per-object namespace with
+  # the object upon object construction -> no NsColonVarResolver(),
+  # InterpColonVarResolver() is responsible!
+  # 2. an explicit per-object namespace creation using [:require
+  # namespace] -> NsColonVarResolver() is put in place!
+  # 3. Object get per-object members (fields, methods) ->
+  # NsColonVarResolver() is put in place!
+  #
+  # The following test covers scenario 1: Called from within
+  # NsfSetterMethod(), SetInstVar() verifies, whether there is a
+  # per-object namespace (objPtr->nsPtr); if so, TCL_NAMESPACE_ONLY is
+  # set ... in this object/ns alignment scenario,
+  # InterpColonVarResolver() (!) serves the var resolution request. It
+  # effectively forward-passes the resolution request when sensing
+  # TCL_NAMESPACE_ONLY by signalling TCL_CONTINUE. This is a consequence
+  # of handling the "compiled [variable] vs. AVOID_RESOLVERS" case
+  # InterpColonVarResolver(). As in colon-prefixed calls to the setter
+  # method (via ColonCmd()), the colon prefix is present in the
+  # name-carrying Tcl_Obj used to in SetInstVar(). As we set an object
+  # frame context, we effectively end up with a colon-prefixed object
+  # variable :(
+  
+  Class create Omon
+  ::nsf::setter Omon a1
+  
+  namespace eval omon {}
+  Omon create omon
+  omon a1 ""
+  ? {omon info vars a1} "a1"
+  ? {omon info vars :a1} ""
+  omon eval {
+    :a1 ""
+    ? [list [current] info vars a1] "a1"
+    # Prior to the fix, [:info vars] would have returned ":a1"
+    ? [list [current] info vars :a1] "" 
+  }
+}