The computer has been worrying me a bit lately. There have been a couple of occasions lately when instead of starting up like normally, the screen just stayed dark and multiple beeps were heard. According to an Apple support document, this points to bad RAM, but a run-through with the Apple hardware test CD showed nothing out of the ordinary.
I had put a piece of foam behind the computer to dampen the sound from the fan, and thinking this was the problem, I removed it. The issues seemed to stop, though admittedly, I don't restart it often enough to do exhaustive comparative testing. In any case, I noticed a much stranger problem today when I booted it up after having it unhooked since we were having some electricity wires, uh, rewired; it booted with the sound turned to 11, literally. The sound was much louder than I've ever heared it go normally. Playing around a bit with the volume seemed to fix it, but then when I tried to play an MP3 the volume went right back up through the roof.
So I started thinking: what had I done recently, had I changed anything? Yes. I had changed the resolution of the screen. Reboot, change resolution. Haven't seen any of the previously mentioned problems yet.
Of course, that makes no sense that just changing the resolution would have such a drastic effect on the system. But who knows? Changing the resolution also changes the frequency that the screen updates, so maybe the new lower frequence just gave off some "bad vibes"...