Index: generic/xotcl.c
===================================================================
diff -u -rc942f4e117d2aa3c8594702e0476a3f73a4147df -re5cee71c4fdd11860c1a897522c6d4202ebc64c4
--- generic/xotcl.c	(.../xotcl.c)	(revision c942f4e117d2aa3c8594702e0476a3f73a4147df)
+++ generic/xotcl.c	(.../xotcl.c)	(revision e5cee71c4fdd11860c1a897522c6d4202ebc64c4)
@@ -12393,11 +12393,16 @@
 
   result = ArgumentCheck(interp, value, paramPtr, &flags, &checkedData, &outObjPtr);
 
+  if (value != outObjPtr) {
+    Tcl_ResetResult(interp);
+  }
+
   if (flags & XOTCL_PC_MUST_DECR) {
     DECR_REF_COUNT(outObjPtr);
   }
-  
+
   Tcl_SetIntObj(Tcl_GetObjResult(interp), (result == TCL_OK));
+
   return TCL_OK;
 }
 
Index: tests/parameters.xotcl
===================================================================
diff -u -rc942f4e117d2aa3c8594702e0476a3f73a4147df -re5cee71c4fdd11860c1a897522c6d4202ebc64c4
--- tests/parameters.xotcl	(.../parameters.xotcl)	(revision c942f4e117d2aa3c8594702e0476a3f73a4147df)
+++ tests/parameters.xotcl	(.../parameters.xotcl)	(revision e5cee71c4fdd11860c1a897522c6d4202ebc64c4)
@@ -38,6 +38,24 @@
 ? {::xotcl::valuecheck lower Abc} 0 "no lower case chars"
 ? {string is lower abc} 1 "tcl command 'string is lower'"
 
+#######################################################
+# valuecheck
+#######################################################
+Test case valuecheck
+Test parameter count 10000
+
+Object create ::paramManager {
+  :method type=sex {name value} {
+    return "agamous"
+  }
+}
+
+? {::xotcl::valuecheck sex,slot=::paramManager female} "1"
+::paramManager destroy
+
+#######################################################
+# cononical feature table
+#######################################################
 #
 # parameter options
 #   required