That doesn't (to me, at least) explain why it never crashes except under the one case, nor why I was told by zope.com that this had been seen before with RDBMS extensions. I'm entirely open to the idea of improper memory or reference management, but I'd suspect that, since the extension is a constant, that crashes would appear in all cases. That not being the case, I suspect the environment that's setting up the thread -- Python, in this case. If it *is* a matter of the extension itself, then an example of how it should properly be done would be in order. I've not seen any. ---------- Keith J. Farmer kfarmer@thuban.org http://www.thuban.org -----Original Message----- From: Chris McDonough [mailto:chrism@zope.com] Sent: Monday, January 28, 2002 16:00 I don't think it has anything to do with C extensions in general (Zope has lots of those, and for the most part, we think they work OK). I think it has to do with particular C extensions that are coded improperly and thus cause segfaults. A "usual suspect" in those cases that there would be improper memory and/or reference management.