[Zope] help! too many open files (zope-2.3.1)

hi all i've been running zope-2.3.1 for quite some time now. everything went well. but the isp had a power failure today. and after that i kept getting too many open files, esp with access of mailhost, localfs, etc. i've increased the file-max in /proc/sys/fs/file-max. ulimit -a tells me that i can only have 1024 file open. if i restart zope, everything's ok. but the problem will appear again is this the problem? setup - zope-2.3.1 rh 6.2 zeo-0.5 thanks