I would look in ObjecManager.py / manage_main()
But try the simple things first. Try removing all your own manage tabs and just use the defaults from your parent classes.
like this:
manage_options = ObjectManager.manage_options\ + RoleManager.manage_options + Item.manage_options
If this gives you trouble, you should look elsewhere for your error.
it did give me trouble. the solution was to remove 'meta_types' from my class and apparently inherit it from ObjectManager. the method ObjectManager.filter_meta_types was attempting to use .has_key('...') on my tuple of metatypes (which were strings). i am unclear as to where zope translates these strings to some other object. as for the manage_options, i used a bastardized version of the Folder class'. it works, but i am still unclear about the details. -bob