The crash happens if an Exception doesn't
have a dict, in BaseException_reduce.
Example:

Python 2.5a2 (trunk:46539M, May 30 2006, 05:02:24)
[MSC v.1310 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license"
for more information.
>>> import pickle
>>> e = BaseException()
>>> pickle.dumps(e) # crash

I'm attaching a module with this and some
other failing tests, mostly caused by
backward incompatibilities. All of the
tests pass on 2.5a2.