[Zope] Beta -problem

Hello, while starting Zope this morning I got this message.Yestersday I installed the newest beta. ->Traceback (innermost last): File "C:\Programme\Zopista\z2.py", line 554, in ? exec "import "+MODULE in {} File "<string>", line 1, in ? File "C:\Programme\Zopista\lib\python\Zope\__init__.py", line 94, in ? import ZODB, ZODB.ZApplication, imp File "C:\Programme\Zopista\lib\python\ZODB\__init__.py", line 85, in ? import sys, ExtensionClass, TimeStamp, cPersistence, Persistence ImportError: No module named ExtensionClass -- Sent through GMX FreeMail - http://www.gmx.net