[mod_python] mod_python.publisher undeterministic behavior

Well, here's the problem. Publisher handler is behavig very
undeterministic with some user folders at my university labs
(mod_python2.7, python 2.1). Sometimes i just get the 404 error, while
other times (rarely) it works fine. The files and folders are the
same, and i don't know what could be wrong. I have almost the same
server running at home (mod_python 2.7, mod_python 2.4).
How could i solve this?
thanks,
tuza