OK. Around 8:45 PM we went off-line again.
There was a weird crash related to the fact that we filled up a hard drive. I'm not pointing any fingers (this time) but you people be nice.
I'm just kidding. It was a configuration issue with RedHat linux defaults and the way vBulletin sets permissions. We've got it fixed now (I think) but we still may have database hiccups from time to time. At least they shouldn't be as frequent as before, though...
[update 4/9/2005]
Though I'm sure no one will read this, we had another hiccup at 7:00AM today when I rebooted our webserver. Seems we had filled up the log files already. Redhat is not high on my happiness list right now...