Index: TODO
===================================================================
diff -u -re979a7fbb725c874f4900258e7537aaf29c0fbae -r2ca66aec9ed16d36076d6b9c959642ee13d08647
--- TODO	(.../TODO)	(revision e979a7fbb725c874f4900258e7537aaf29c0fbae)
+++ TODO	(.../TODO)	(revision 2ca66aec9ed16d36076d6b9c959642ee13d08647)
@@ -2191,6 +2191,7 @@
 - xotcl2.tcl: defined ::xotcl::MetaSlot
 - make sure, that classes of the intrinsic class hierarchy are 
   of the same object system
+- add regression test
 
 TODO:
 - doc:
Index: tests/contains.test
===================================================================
diff -u -ra16377a1a6ba5a51fa50b775312c066f3ba5e8fc -r2ca66aec9ed16d36076d6b9c959642ee13d08647
--- tests/contains.test	(.../contains.test)	(revision a16377a1a6ba5a51fa50b775312c066f3ba5e8fc)
+++ tests/contains.test	(.../contains.test)	(revision 2ca66aec9ed16d36076d6b9c959642ee13d08647)
@@ -104,4 +104,25 @@
 package forget XOTcl
 package require XOTcl
 
+########################################################################
+#
+# Test that we do not allow to mix object systems within the intrinsic
+# classes of an object. Otherwise we would have problems with the
+# recreate "C0 create c0". On a recreate of c0 the object system for
+# C0 is ::xotcl, therefore we try to call recreate. In the C0 class
+# hierarchy is from nx and contains no "recreate" method.
+
+# trigger the call of "cleanup" to work via method dispatch
+::xotcl::Object create o1
+o1 proc cleanup {} {return}
+
+? {catch {::xotcl::Class create C0 -superclass ::nx::Object} errorMsg} 1
+? {set ::errorMsg} {class "::C0" has different object system as class  "::nx::Object"}
+::nx::Class create C1 -superclass ::nx::Object
+
+#C0 create c0
+#C0 create c0
+C1 create c1
+C1 create c1
+
 #puts stderr ===EXIT
\ No newline at end of file