Ahh...So it has the potential for being 2 different things. That sucks :/ Where did you find the info for the beep codes? I searched around for a few hours and didn't turn anything up.
So here's what I did the other day. I had re-installed my 2 sticks of ram putting my system back up to 2 gigs, and started having problems again right away. I took the ram back out, but was still having the same problems. After a day of constant freezing, and my monitor just simply losing a signal, I took out my video card and re-inserted it. That was about 4 days ago, and I haven't had any problems since. Even after hours of gaming the other day too.