I think Ive seen this before, when Product initialization modifies a persistent object, then causes an exception (ImportError, or whatever). You see these ConflictErrors if a subsequent Product initialization also modifies a persistent object.
Hmmm... bit strange that going into /var and doing an rm * and then starting Zope proved a very effective way of eradicating this problem. Sadly it also removes all your data ;-)
I guess the transaction in which that first product was initialized was not correctly aborted.
Is that likely to be a Zope bug?
Ive not looked at this in detail, since its only a problem if you have broken products. My priority has always been to unbreak them....
Well, to my knowledge, none of the products were broken, so... cheers, Chris