Index: Src/Packages/Gui/CoreBindings/Src/ExtendRegistry.inl
===================================================================
--- Src/Packages/Gui/CoreBindings/Src/ExtendRegistry.inl	(revision 6258)
+++ Src/Packages/Gui/CoreBindings/Src/ExtendRegistry.inl	(working copy)
@@ -112,6 +112,8 @@
     {
         ExtendRegistry::AddInterface(type, Core::TypeOf<INotifyCollectionChanged>(),
             Core::CalculateParentOffset<ProxyExtendObservableList, INotifyCollectionChanged>());
+        ExtendRegistry::AddInterface(type, Core::TypeOf<IList>(),
+            Core::CalculateParentOffset<ProxyExtendObservableList, IList>());
     }
 
     typedef ProxyExtendObservableList Type;