My Zimbra is back fully working again now. I upgraded to the latest version(4.5.6_GA_1044.FC5_20070706162711), and tried deleting '/opt/zimbra/clamav/db'. I can't say if that did anything, and I suspect not. Trying to restart zimbra, running a virus db update and restarting just the av part still resulted in the same error. The only way to get things going was by manually creating the pid file.
However after a reboot, everything was up and running, and subsequents restarts of Zimbra have been fine. It's been happy for a couple of weeks now. I hate when reboots fix things.. feels so windows
