Again following up to my own posting ... New information: I found the real Problem. Now I would like an explanation and a workaround ... To recapitulate: I have to Zope setups, our development setup, which is working and a new setup which fails. Both use the same Zope and ZEO version. There is one notable difference: The development setup is running on port 8080, the new setup must run on port 80. Therefore, our development setup is started as user zope (using su) whereas the new setup is started as user root with the -u zope options. I know, I should put a proxy before Zope, but this new setup is for in-house use only, and therefore I thought the proxy not to be necessary. The Moment I start the new setup on port 8080 with su, the ZEO connection starts working !! What the heck ... I really cannot fathom the reason for the observer behavior: o started as root with -u zope and no ZEO: working o started as zope with su and no ZEO: working o started as zope with su and ZEO: working o started as root with -u zope and ZEO: *NOT* working And to reiterate: Not working means, that python just wont start the additional service threads: start_new_thread is called successfully in ../ZRendezvous.py but the new thread never starts executing the code from ../ZServerPublisher.py. So: I think I'll have to delve into pound as proxy, but I really would like an explanation for this behavior ... I don't get it ... Very baffled and curious, Stefan. -- Stefan Bund, Dipl.Phys. a r T e c _____ Entwicklung, Administration visual solutions / | /| |----/_| sbund@artec-berlin.com | / | / Fon: 030 / 884684-0 | Fax: 030 / 884684-15 |/___|/ Gottfried-von-Cramm-Weg 35-37 | Berlin | 14193 | http://www.artec-berlin.com