I had similar problem with zope 2.5.0 and 2.5.1b1 crashing all the time it was a real pain and really embarrassing (luckily still beta testing). After experimenting around we narrowed it down to the fact the crashes seemed to happen when two of us tried to write (possibly) to the postgres database (using ZPoPy 2.0.8). We could more or less make it happen at will doing with two people on at the same time. My solution: in z2.py set NUMBER_OF_THREADS=1 instead of 4 (default). This fixed it completely never had a crash since. Performance doen't seem affected either although haven't really stress tested performance (we did stress test for crashing and it was fine). My guess is that the problem is in ZPoPy although I'm not sure. When I get the chance I will do a more thorough check and send it to the collector. Good luck and let us know how it goes. I must admit I really hoped that going to 2.5.1b1 would solve the crashing problems, the whole thing seriously made me think twice about zope in a production environment. Zahid -- -------------------------------------------------------------------- Dr Zahid Malik Tel: +44 (0) 20 7594 6336 Research Fellow Fax: +44 (0) 20 7581 4419 Dept. of Electrical Eng. Email: z.malik@-NOSPAMPLEASE-ic.ac.uk Imperial College http://infoeng.ee.ic.ac.uk/~malikz Exhibition Road London SW7 2BT