Index: generic/xotcl.c
===================================================================
diff -u -r4cc0fdfb65a5ef8d28eb623084910447849edd7f -r5ab730ebd0e769e5f376cc2db8aa22b024a9c498
--- generic/xotcl.c	(.../xotcl.c)	(revision 4cc0fdfb65a5ef8d28eb623084910447849edd7f)
+++ generic/xotcl.c	(.../xotcl.c)	(revision 5ab730ebd0e769e5f376cc2db8aa22b024a9c498)
@@ -765,9 +765,9 @@
 
 
 /* search for tail of name */
-static char *
-NSTail(char *string) {
-  register char *p = string+strlen(string);
+static CONST char *
+NSTail(CONST char *string) {
+  register char *p = (char *)string+strlen(string);
   while (p > string) {
     if (*p == ':' && *(p-1) == ':') return p+1;
     p--;
@@ -1700,7 +1700,7 @@
   Tcl_Obj *key;
   Tcl_CallFrame *varFramePtr;
   Var *newVar;
-  
+ 
   /* Case 1: The variable is to be resolved in global scope, proceed in
    * resolver chain (i.e. return TCL_CONTINUE)
    *
@@ -1740,36 +1740,32 @@
             varFramePtr->nsPtr->fullName);
     return TCL_CONTINUE;
   }
+  
+  /*
+   * Check for absolutely/relatively qualified variable names, i.e.
+   * make sure that the variable name does not contain any namespace qualifiers. 
+   * Proceed with a TCL_CONTINUE, otherwise.
+   */
 
+  if ((*name == ':' && *(name+1) == ':') || NSTail(name) != name) {
+    return TCL_CONTINUE;
+  }
+  
   /* Case 3: Does the variable exist in the per-object namespace? */
   *varPtr = (Tcl_Var)LookupVarFromTable(Tcl_Namespace_varTable(ns),name,NULL);
 
-  /*
-  fprintf(stderr, "var with name '%s' to be created, flags=%.8X, ns=%p is create %d\n", name,flags,ns,
-          RUNTIME_STATE(interp)->createVarHack);
-  */
-
-  if(*varPtr == NULL 
-     /*
-     && (RUNTIME_STATE(interp)->createVarHack || flags & TCL_NAMESPACE_ONLY)
+  if(*varPtr == NULL) {  
+    /* We failed to find the variable so far, therefore we create it
+     * here in the namespace.  Note that the cases (1), (2) and (3)
+     * TCL_CONTINUE care for variable creation if necessary.
      */
-     ) {  
-    /* We failed to find the variable in the namespace, so we create
-     * it here in the namespace.  Note that the cases (1) and (2) TCL_CONTINUE care
-     * for creation if necessary.
-     *
-     * Note: Essentially, this statement block resembles what
-     * happens in TclLookupSimpleVar() etc., but uses XOTcl-specific
-     * helpers. We acquire a Tcl_Var eagerly, the
-     * variable is later cleared if not defined effectively
-     *   SURE?
-     * (read TclIsVarUndefined == 1). Eagerness is required to support
-     * variable traces etc.
-     *   
-     */
 
-    key = Tcl_NewStringObj(name, -1); /* TODO: check reference counting */
+    key = Tcl_NewStringObj(name, -1);
+
+    INCR_REF_COUNT(key);
     newVar = VarHashCreateVar(Tcl_Namespace_varTable(ns), key, &new);
+    DECR_REF_COUNT(key);
+
 #if defined(PRE85)
     newVar->nsPtr = (Namespace *)ns;
 #endif
@@ -2141,7 +2137,7 @@
 }
 
 void
-XOTclAddPMethod(Tcl_Interp *interp, XOTcl_Object *obji, char *nm, Tcl_ObjCmdProc *proc,
+XOTclAddPMethod(Tcl_Interp *interp, XOTcl_Object *obji, CONST char *nm, Tcl_ObjCmdProc *proc,
                 ClientData cd, Tcl_CmdDeleteProc *dp) {
   XOTclObject *obj = (XOTclObject*) obji;
   Tcl_DString newCmd, *cptr = &newCmd;
@@ -2152,7 +2148,7 @@
 }
 
 void
-XOTclAddIMethod(Tcl_Interp *interp, XOTcl_Class *cli, char *nm,
+XOTclAddIMethod(Tcl_Interp *interp, XOTcl_Class *cli, CONST char *nm,
                 Tcl_ObjCmdProc *proc, ClientData cd, Tcl_CmdDeleteProc *dp) {
   XOTclClass *cl = (XOTclClass*) cli;
   Tcl_DString newCmd, *cptr = &newCmd;
@@ -7265,7 +7261,7 @@
  */
 
 static int
-unsetInAllNamespaces(Tcl_Interp *interp, Namespace *nsPtr, char *name) {
+unsetInAllNamespaces(Tcl_Interp *interp, Namespace *nsPtr, CONST char *name) {
   int rc = 0;
   fprintf(stderr, "### unsetInAllNamespaces variable '%s', current namespace '%s'\n", 
           name, nsPtr ? nsPtr->fullName : "NULL");
@@ -8146,8 +8142,8 @@
     cxtNsPtr = Tcl_GetCurrentNamespace(interp);
   }
 
-  TclGetNamespaceForQualName(interp, name, (Namespace *) contextNsPtr,
-                             flags, &nsPtr[0], &nsPtr[1], &cxtNsPtr, &simpleName);
+  TclGetNamespaceForQualName(interp, name, (Namespace *) contextNsPtr,flags, 
+                             &nsPtr[0], &nsPtr[1], &cxtNsPtr, &simpleName);
 
   /*fprintf(stderr, "  ***Found %s, %s\n", nsPtr[0]->fullName, nsPtr[0]->fullName);*/
 
@@ -8433,7 +8429,7 @@
   if (objc != 2) return XOTclObjErrArgCnt(interp, obj->cmdName, "exists var");
 
   Tcl_SetIntObj(Tcl_GetObjResult(interp), 
-                varExists(interp, obj, ObjStr(objv[1]), NULL, 0, 1));
+                varExists(interp, obj, ObjStr(objv[1]), NULL, 1, 1));
   return TCL_OK;
 }
 
@@ -9423,7 +9419,6 @@
   }
   if (tcd->objscope) {
     XOTcl_PushFrame(interp, tcd->obj);
-    RUNTIME_STATE(interp)->createVarHack = 1;
   }
   if (tcd->objProc) {
     result = (tcd->objProc)(tcd->cd, interp, objc, objv);
@@ -9438,7 +9433,6 @@
 
   if (tcd->objscope) {
     XOTcl_PopFrame(interp, tcd->obj);
-    RUNTIME_STATE(interp)->createVarHack = 0;
   }
   return result;
 }
@@ -11603,8 +11597,8 @@
   XOTclObject *obj = (XOTclObject*) cd;
   Tcl_Obj *o = obj->cmdName;
   int result = TCL_ERROR;
-  char *fullName = ObjStr(o);
-  char *vn;
+  CONST char *fullName = ObjStr(o);
+  CONST char *vn;
   callFrameContext ctx = {0};
 
   if (objc != 1) 
Index: generic/xotcl.decls
===================================================================
diff -u -rf4b1378f3136bc998645f230af38847bcf76d96b -r5ab730ebd0e769e5f376cc2db8aa22b024a9c498
--- generic/xotcl.decls	(.../xotcl.decls)	(revision f4b1378f3136bc998645f230af38847bcf76d96b)
+++ generic/xotcl.decls	(.../xotcl.decls)	(revision 5ab730ebd0e769e5f376cc2db8aa22b024a9c498)
@@ -57,12 +57,12 @@
 }
 declare 11 generic {
     void XOTclAddPMethod(Tcl_Interp* in, struct XOTcl_Object* obj, 
-                         char* nm, Tcl_ObjCmdProc* proc,
+                         CONST char* nm, Tcl_ObjCmdProc* proc,
 	                 ClientData cd, Tcl_CmdDeleteProc* dp)
 }
 declare 12 generic {
     void XOTclAddIMethod(Tcl_Interp* in, struct XOTcl_Class* cl, 
-                         char* nm, Tcl_ObjCmdProc* proc,
+                         CONST char* nm, Tcl_ObjCmdProc* proc,
 	                 ClientData cd, Tcl_CmdDeleteProc* dp)
 }
 declare 13 generic {
Index: generic/xotclDecls.h
===================================================================
diff -u -rbfeda566de60595825c75d78632d42458bb6cb05 -r5ab730ebd0e769e5f376cc2db8aa22b024a9c498
--- generic/xotclDecls.h	(.../xotclDecls.h)	(revision bfeda566de60595825c75d78632d42458bb6cb05)
+++ generic/xotclDecls.h	(.../xotclDecls.h)	(revision 5ab730ebd0e769e5f376cc2db8aa22b024a9c498)
@@ -53,12 +53,12 @@
 				struct XOTcl_Class* cl));
 /* 11 */
 EXTERN void		XOTclAddPMethod _ANSI_ARGS_((Tcl_Interp* in, 
-				struct XOTcl_Object* obj, char* nm, 
+				struct XOTcl_Object* obj, CONST char* nm, 
 				Tcl_ObjCmdProc* proc, ClientData cd, 
 				Tcl_CmdDeleteProc* dp));
 /* 12 */
 EXTERN void		XOTclAddIMethod _ANSI_ARGS_((Tcl_Interp* in, 
-				struct XOTcl_Class* cl, char* nm, 
+				struct XOTcl_Class* cl, CONST char* nm, 
 				Tcl_ObjCmdProc* proc, ClientData cd, 
 				Tcl_CmdDeleteProc* dp));
 /* 13 */
@@ -167,8 +167,8 @@
     int (*xOTclCreateClass) _ANSI_ARGS_((Tcl_Interp* in, Tcl_Obj* name, struct XOTcl_Class* cl)); /* 8 */
     int (*xOTclDeleteObject) _ANSI_ARGS_((Tcl_Interp* in, struct XOTcl_Object* obj)); /* 9 */
     int (*xOTclDeleteClass) _ANSI_ARGS_((Tcl_Interp* in, struct XOTcl_Class* cl)); /* 10 */
-    void (*xOTclAddPMethod) _ANSI_ARGS_((Tcl_Interp* in, struct XOTcl_Object* obj, char* nm, Tcl_ObjCmdProc* proc, ClientData cd, Tcl_CmdDeleteProc* dp)); /* 11 */
-    void (*xOTclAddIMethod) _ANSI_ARGS_((Tcl_Interp* in, struct XOTcl_Class* cl, char* nm, Tcl_ObjCmdProc* proc, ClientData cd, Tcl_CmdDeleteProc* dp)); /* 12 */
+    void (*xOTclAddPMethod) _ANSI_ARGS_((Tcl_Interp* in, struct XOTcl_Object* obj, CONST char* nm, Tcl_ObjCmdProc* proc, ClientData cd, Tcl_CmdDeleteProc* dp)); /* 11 */
+    void (*xOTclAddIMethod) _ANSI_ARGS_((Tcl_Interp* in, struct XOTcl_Class* cl, CONST char* nm, Tcl_ObjCmdProc* proc, ClientData cd, Tcl_CmdDeleteProc* dp)); /* 12 */
     void (*xOTclRemovePMethod) _ANSI_ARGS_((Tcl_Interp* in, struct XOTcl_Object* obj, char* nm)); /* 13 */
     void (*xOTclRemoveIMethod) _ANSI_ARGS_((Tcl_Interp* in, struct XOTcl_Class* cl, char* nm)); /* 14 */
     Tcl_Obj* (*xOTclOSetInstVar) _ANSI_ARGS_((struct XOTcl_Object* obj, Tcl_Interp* in, Tcl_Obj* name, Tcl_Obj* value, int flgs)); /* 15 */
Index: generic/xotclInt.h
===================================================================
diff -u -r4cc0fdfb65a5ef8d28eb623084910447849edd7f -r5ab730ebd0e769e5f376cc2db8aa22b024a9c498
--- generic/xotclInt.h	(.../xotclInt.h)	(revision 4cc0fdfb65a5ef8d28eb623084910447849edd7f)
+++ generic/xotclInt.h	(.../xotclInt.h)	(revision 5ab730ebd0e769e5f376cc2db8aa22b024a9c498)
@@ -472,7 +472,7 @@
   Tcl_HashTable metaData;
 #endif
   ClientData clientData;
-  char *volatileVarName;
+  CONST char *volatileVarName;
   short checkoptions;
 } XOTclObjectOpt;
 
@@ -644,7 +644,6 @@
   int unknown;
   int doFilters;
   int doSoftrecreate;
-  int createVarHack;
   int exitHandlerDestroyRound;
   int returnCode;
   long newCounter;
Index: tests/varresolutiontest.xotcl
===================================================================
diff -u -r4cc0fdfb65a5ef8d28eb623084910447849edd7f -r5ab730ebd0e769e5f376cc2db8aa22b024a9c498
--- tests/varresolutiontest.xotcl	(.../varresolutiontest.xotcl)	(revision 4cc0fdfb65a5ef8d28eb623084910447849edd7f)
+++ tests/varresolutiontest.xotcl	(.../varresolutiontest.xotcl)	(revision 5ab730ebd0e769e5f376cc2db8aa22b024a9c498)
@@ -105,4 +105,30 @@
 ? {o array exists a} 0
 ? {namespace eval ::o array exists a} 0
 
+o destroy
+
+###########################################
+# tests on namespace-qualified var names
+###########################################
+
+Object o -requireNamespace
+Object o::oo -requireNamespace
+
+? {::o set ::x 1} 1
+? {info exists ::x} [set ::x]
+? {catch {unset ::x}} 0 1
+
+? {::o set ::o::x 1} 1
+? {o exists x} [::o set ::o::x]
+? {namespace eval ::o unset x} "" 1
+? {o exists x} 0
+
+# Note, relatively qualified var names (not prefixed with ::*) 
+# are always resolved relative to the per-object namespace
+? {catch {::o set o::x 1} msg} 1
+? {::o set oo::x 1} 1
+? {o::oo exists x} [::o set oo::x]
+? {o unset oo::x} "" 1
+? {o::oo exists x} 0
+
 o destroy
\ No newline at end of file