[Zope-CMF] problems using SkinnedFolders / CMFForum

[Robert Rottermann]

When I try to create Post instance in a CMFForum-Folder I get an error that

Error Type: AttributeError
Error Value: DateTime instance has no __call__ method

Hunting down the problem I found the following peculiarity:

The error happens in Post's factory when (in _setObject, manage_afterAdd)
when accessing Date.

in CMFForum self.modified is a DateTime instance
>>> type(self.modified)
<type 'instance'>

when adding a CMF-document, then self.modified is a method.
>>> type(self.modified)
<type 'Python Method'>
>>>

runjaga hinted that some optimisation done for CMF1.3 provoke errors in
conjunction with folders that inherit from SkinnedFolders (as CMFFolder
does).

Can anyone tell me more what could be the reason, and how to rectify the
problem?