Apparently, my rig doesn't like to run at night anymore. Tried getting on last night, and it restarted on me numerous times. Couldn't stay more than 2 minutes, literally. This morning it ran fine for about 15-20 minutes before I left for work. I'm about at my wit's end with this thing - I may have to bite the bullet and buy a new mobo, even though I don't want to since I haven't pinpointed that as the problem.