[Zope-dev] ZODB Couldn't load state (Berkeley DB 2..7.7)

I have been using Berkeley DB 2.7.7 as main Zope Storage for about 3 months now. I am running Zope 2.2.4. Everything was fine yesterday. This morning I tried to access a ZClass (base class ZObjectManager), which contains about 2,000 objects, I got ERROR(200) ZODB Couldn't load state for '\000\000\000\000\000\000\026\351' Traceback (innermost last): File /usr/local/zope/2-2/lib/python/ZODB/Connection.py, line 448, in setstate cPickle.UnpicklingError: invalid load key, ''. Other than this ZClass, I can access other objects just fine. I tried Ty's tranalyzer. But it gave me "error: Not a .fs file (at least, not a kind I know about)". How can I recover the 2,000 objects? Regards, Ping