http://bugs.winehq.org/show_bug.cgi?id=24812
--- Comment #1 from A Wine user RandomAccountName@mail.com 2010-10-21 14:01:33 CDT --- I should have noticed this sooner, but these two lines are printed each time the buggy right-click menu is opened in a real directory:
err:ole:CoGetClassObject class {d969a300-e7ff-11d0-a93b-00a0c90f2719} not registered err:ole:CoGetClassObject no class object {d969a300-e7ff-11d0-a93b-00a0c90f2719} could be created for context 0x1
In areas where the bug doesn't appear (My Computer and Control Panel), these lines don't appear when opening the menu, either.