Index: TODO
===================================================================
diff -u -N -r9a578692ecf2d05eb4da0de37c7e0bdca3819570 -r3696772f6383ca87f6f4c7716a12843afacdff2f
--- TODO	(.../TODO)	(revision 9a578692ecf2d05eb4da0de37c7e0bdca3819570)
+++ TODO	(.../TODO)	(revision 3696772f6383ca87f6f4c7716a12843afacdff2f)
@@ -1964,6 +1964,10 @@
    * just show warning and errors when rebuilding pkgIndex files 
    * stop make in case of errors in pkg_mkIndex
 
+- Fixed switching between INACTIVE_MIXIN frames to ACTIVE_MIXIN frames
+- Extended regression test
+
+
 TODO:
 
 - "-returns" 
Index: generic/nsf.c
===================================================================
diff -u -N -r7ac9328ee6b3fd77da6da4235e10f29c3c4513de -r3696772f6383ca87f6f4c7716a12843afacdff2f
--- generic/nsf.c	(.../nsf.c)	(revision 7ac9328ee6b3fd77da6da4235e10f29c3c4513de)
+++ generic/nsf.c	(.../nsf.c)	(revision 3696772f6383ca87f6f4c7716a12843afacdff2f)
@@ -9176,7 +9176,7 @@
      */
     if (object->mixinStack) {
       if (cscPtr->frameType == NSF_CSC_TYPE_ACTIVE_MIXIN)
-        cscPtr->frameType = NSF_CSC_TYPE_INACTIVE;
+        cscPtr->frameType = NSF_CSC_TYPE_INACTIVE_MIXIN;
 
       /* otherwise move the command pointer forward */
       if (isMixinEntry) {
@@ -15319,6 +15319,7 @@
   if (object && (object->filterStack || object->mixinStack) ) {
     CallStackUseActiveFrame(interp, &ctx);
   }
+
   if (!Tcl_Interp_varFramePtr(interp)) {
     CallStackRestoreSavedFrames(interp, &ctx);
     return NsfVarErrMsg(interp, "instvar used on ", objectName(object),
Index: tests/varresolution.test
===================================================================
diff -u -N -r84c5ee62a46e8fab7b9cc481c87290d387baced9 -r3696772f6383ca87f6f4c7716a12843afacdff2f
--- tests/varresolution.test	(.../varresolution.test)	(revision 84c5ee62a46e8fab7b9cc481c87290d387baced9)
+++ tests/varresolution.test	(.../varresolution.test)	(revision 3696772f6383ca87f6f4c7716a12843afacdff2f)
@@ -1073,8 +1073,32 @@
     
     ? {::ns1::o bar} "1-1-:XXX-"
   }
+}
 
+Test case after-next {
+  #
+  # This test case tests, whether we can use e..g an instvar in an
+  # mixin method after the next. In such cases, the frame flags have
+  # to be altered from inactive mixin to active mixin (otherwise the
+  # actual frame would be skipped in useActiveFrames below in :instvar).
+  #
+  Class create FormPage {
+    :attribute package_id
+    :public method initialize_loaded_object {} {;}
+  }
 
+  Class create WorkflowPage {
+    :alias instvar :::nsf::methods::object::instvar
+    :public method initialize_loaded_object {} {
+      next
+      :instvar package_id
+      return $package_id
+    }
 
+    FormPage mixin WorkflowPage
+    FormPage create p1 -package_id 123
+    
+    ? {p1 initialize_loaded_object} 123
+  }
+}
 
-}
\ No newline at end of file