Hi Tony No, I havn't solved the problem but after restarting production (after 19 days) I noticed that the funny way the threadcount reacted. I'd say, that the threads don't get killed after they have finished. I also noticed that the memory use went down from 344Mb to about 26Mb. Now I've put a restart into my nightly cronjob. (Are there some reasons why Zope should not be restarted dayly?????) I've just tested the whole thing on a WinNT 4.0 PC with Zope 2.4.2 (binary distribution). No problems! The PC gets slower but can answer two browser instances parallel. If I do the same thing on Solaris (intel & sun servers!) it is impossible! Normally you have sortof a break in a loop where control is given to the other parallel threads. This seems not to happen on my source compile with Solaris. I'm not so firm on where to address this problem (or if the problem was already adressed elswhere e.g. python maillists). Therefore I'd really apreciate some help! ;-) I don't want to start thinking about a migration Linux or even (puke) Windows. On Solaris I'm still using 2.4.0. Does it make sense to upgrade? I've seen that in Zope 2.4.3b1 there was some issue with dtml-recursion? Greetings from a rany Cologne! Oliver -- GMX - Die Kommunikationsplattform im Internet. http://www.gmx.net