[Zope] Import Error ZServer, ZODB

I have seen the following a couple of times on my Windows 95 laptop (my learning system). Once with Zope 2.01 and also with the latest Zope2.1 Beta2. After I do some work - like going through the "Boring" example and the Plutonia tutorial, the next time I attempt to restart Zope - it gives me an error to the effect that import Zserver line fails in z2.py. I reinstalled Zope and things start to work. The time before, it was import ZODB failure. Is this peculiar to Win95 or I am doing something illegal? Thanks.