Index: generic/nsf.c
===================================================================
diff -u -rbf363a408bfa522970f24b06967f2091604b6d02 -r05d94a270a6c11715c96ddbbe441160e9fd63d42
--- generic/nsf.c	(.../nsf.c)	(revision bf363a408bfa522970f24b06967f2091604b6d02)
+++ generic/nsf.c	(.../nsf.c)	(revision 05d94a270a6c11715c96ddbbe441160e9fd63d42)
@@ -1567,20 +1567,21 @@
     for (entryPtr = *firstPtrPtr; entryPtr; prevPtr = entryPtr, entryPtr = entryPtr->nextPtr) {
       if ((void *)entryPtr->cl == key) {
 	/* found entry */
-	if (prevPtr) {
-	  /* later item */
-	  prevPtr->nextPtr = entryPtr->nextPtr;
-	} else {
-	  /* first item */
-	  *firstPtrPtr = entryPtr->nextPtr;
-	}
+	  if (prevPtr) {
+	    /* later item */
+	    prevPtr->nextPtr = entryPtr->nextPtr;
+	  } else {
+	    /* first item */
+	    *firstPtrPtr = entryPtr->nextPtr;
+	  }
 	break;
       }
     }
   }
 
   return entryPtr;
 }
+
 #endif
 
 
@@ -8681,11 +8682,11 @@
 #if defined(NRE)
   if (validCscPtr) {
     //fprintf(stderr, "forced finalize 2 cscPtr %p\n", cscPtr);
-    CscListRemove(interp, cscPtr);
+    CscListRemove(interp, cscPtr, NULL);
     CscFinish(interp, cscPtr, result, "csc cleanup");
   }
 #else
-  CscListRemove(interp, cscPtr);
+  CscListRemove(interp, cscPtr, NULL);
   CscFinish(interp, cscPtr, result, "csc cleanup");
 #endif
 
@@ -9093,7 +9094,7 @@
 
     //fprintf(stderr, "forced finalize 1 cscPtr %p objc %d %p\n", cscPtr, cscPtr->objc, cscPtr->objv);
     result = ObjectDispatchFinalize(interp, cscPtr, result /*, "immediate" , methodName*/);
-    CscListRemove(interp, cscPtr);
+    CscListRemove(interp, cscPtr, NULL);
     CscFinish(interp, cscPtr, result, "non-scripted finalize");
   }
 
@@ -11959,16 +11960,17 @@
  *----------------------------------------------------------------------
  * NextSearchAndInvoke --
  *
- *    The function is called with a final argument vector and searches
- *    for an possible shadowed method. In case is successful, it
- *    updates the continuation context (filter flags etc), invokes
- *    the found method, and performs cleanup.
+ *    The function is called with a final argument vector and searches for a
+ *    possibly shadowed method. If a target method is found, this dispatcher
+ *    function updates the continuation context (filter flags etc.), invokes
+ *    upon the target method, and performs a cleanup.
  *
  * Results:
  *    Tcl return code
  *
  * Side effects:
- *    The invoked method might produce side effects
+ *    The invoked method might produce side effects. Also, the interp's unknown
+ *    state may be modified.
  *
  *----------------------------------------------------------------------
  */
@@ -12073,16 +12075,38 @@
 			    object, cl, methodName, frameType, 0);
 #endif
   } else if (result == TCL_OK) {
+    NsfCallStackContent *topCscPtr = NULL;
+    int isLeafNext;
+    
     /*
-     * We could not find a cmd, but there was no error on the call.
-     * When we are at the end of a filter-chain, or within a next from
-     * an ensemble, set the unknown flag to allow higher levels to
-     * handle this case.
+     * We could not find a cmd, yet the dispatch attempt did not result
+     * in an error. This means that we find ourselves in either of three
+     * situations at this point:
+     *
+     * 1) A next cmd (NsfNextCmd()) at the end of a filter chain: Dispatch to
+     * unknown as there is no implementation for the requested selector
+     * available.  2) A next cmd from within a leaf submethod (a "leaf next"):
+     * Remain silent, do not dispatch to unknown.  3) MethodDispatchCsc()
+     * realises the actual "ensemble next": Dispatch to unknown, the
+     * requested sub-selector is not resolvable to a cmd.
+     *
+     * For the cases 1) and 3), set the interp's unknown flag signalling to
+     * higher levels (e.g., in MethodDispatchCsc(), in NsfNextCmd()) the need
+     * for dispatching to unknown.
      */
+    
+    topCscPtr = CallStackGetTopFrame(interp, NULL);
+    assert(topCscPtr);
+    
+    /* case 2 */
+    isLeafNext = (cscPtr != topCscPtr) && (topCscPtr->frameType & NSF_CSC_TYPE_ENSEMBLE) && 
+      (topCscPtr->flags & NSF_CSC_CALL_IS_ENSEMBLE) == 0;
 
-    /*fprintf(stderr, "--- no cmd, csc %p frameType %.6x callType %.6x endOfFilterChain %d NSF_CSC_CALL_IS_ENSEMBLE %d\n",
-      cscPtr, cscPtr->frameType, cscPtr->flags, endOfFilterChain,(cscPtr->flags & NSF_CSC_CALL_IS_ENSEMBLE)!=0);*/
-    rst->unknown = endOfFilterChain || (cscPtr->flags & NSF_CSC_CALL_IS_ENSEMBLE);
+    /*fprintf(stderr, "--- no cmd, csc %p frameType %.6x callType %.6x endOfFilterChain %d NSF_CSC_CALL_IS_ENSEMBLE %d NSF_CSC_TYPE_ENSEMBLE % d NSF_CSC_CALL_IS_NEXT %d rst->unknown %d isLeafNext %d\n", cscPtr, cscPtr->frameType, cscPtr->flags, endOfFilterChain, (cscPtr->flags & NSF_CSC_CALL_IS_ENSEMBLE) != 0, (cscPtr->frameType & NSF_CSC_TYPE_ENSEMBLE) != 0, (cscPtr->flags & NSF_CSC_CALL_IS_NEXT) != 0, rst->unknown, isLeafNext);*/
+    
+    rst->unknown = /* case 1 */ endOfFilterChain || 
+      /* case 3 */ (!isLeafNext && (cscPtr->flags & NSF_CSC_CALL_IS_ENSEMBLE)); 
+
     /*fprintf(stderr, "******** setting unknown to %d\n",  rst->unknown );*/
   }
 
@@ -19200,12 +19224,12 @@
        * varFramePtr to the previous value.
        */
       Nsf_PopFrameCsc(interp, framePtr2);
-      CscListRemove(interp, cscPtr);
+      CscListRemove(interp, cscPtr, NULL);
       CscFinish(interp, cscPtr, result, "converter object frame");
       Tcl_Interp_varFramePtr(interp) = varFramePtr;
 
-      /*fprintf(stderr, "NsfOConfigureMethod_ attribute %s evaluated %s => (%d)\n",
-        ObjStr(paramPtr->nameObj), ObjStr(newValue), result);*/
+      /* fprintf(stderr, "NsfOConfigureMethod_ attribute %s evaluated %s => (%d)\n",
+	 ObjStr(paramPtr->nameObj), ObjStr(newValue), result);*/
 
       if (result != TCL_OK) {
         Nsf_PopFrameObj(interp, framePtr);