[This message was 1st posted 2 weeks ago on the main zope list.] Hello, I've been playing with ZClasses and I ran into an issue with ZObjectManager. Summary: (when creating a folderish ZClass and cascading base classes) if ZObjectManager isn't subclassed at 1st level, objects can be added to the folderish ZClass instances but they don't show in the manage_main object list. [Zope 2.1.4 on Win32, pure ZClasses, no Python around] More details: 1) I first tried this simple setup. It worked fine: ZClass_for_CatalogAware ZClass_for_Renderable ZObjectManager | |_MyTestClass MyTestClass is folderish and works as expected. 2) This setup worked fine too: ZClass_for_CatalogAware ZClass_for_Renderable ZObjectManager | |_MyBaseClass |_MyTestClass1 |_MyTestClass2 I can create a custom base class and use it in several ZClasses. They are folderish and work as expected. 3) Then I tried this setup: ZClass_for_CatalogAware ZClass_for_Renderable | |_MyBaseClass |_ZObjectManager |_MyTestClass Here I first created MyBaseClass, then I subclassed it together with ZObjectManager when creating MyTestClass. MyTestClass looked OK; I created a Content view linked to manage_main; I allowed adding standard object types such as Folder and File. However, when I add objects in an instance of MyTestClass they do not show in the object list (Content view). I *think* they are actually added because I cannot add an additional one with the same ID: I get an "ID already in use" error. When testing further I got the same results when CatalogAware and Renderable were not around. Same results too when subclassing Folder instead. It's not that bad, but I can't create a standard base class, then use it to create a folderish variant. Does anyone understand why? Cheers. Alexandre