Stability issues with ZCM 11.2.3a imaging

We're running the latest build of ZCM, 11.2.3a on SLES 11. At least once a week, the help desk comes over complaining that the imaging server is down. Sometimes the DHCP proxy stops working, sometimes it's the TFTP server or the pbserv process, other times we can't tell what's wrong... Restarting the services sometimes helps, but not for long (a day or two). Rebooting the server always fixes it, but just for a few days (at best).

Both of our imaging servers are physical boxes, so it's not a VMware-related issue.

I've tried disabling ClamAV, re-installing Tuxera, forcing communication to HTTP, I've checked and re-checked the services for proper startup settings... So far, I'm not getting anywhere.

Any thoughts or general things for us to look at?