Upgraded from FreeBSD 8.x-STABLE to FreeBSD 9.2-PRELEASE. Disaster. Went back to FreeBSD 9.1. Still disaster. Every few hours the kernel panics, and the server reboots. Have completed major changes, went from i368 to amd64. Same bug. Somewhere PF has become unreliable in FreeBSD 9.
Not good. Have used FreeBSD since version, never had these problems.
Not sure what to do now. Probably simply my pf rules, which won't be easy, to see if the problem disappears that way.