Weird. I've had a CPU just die on me as well though.

I was building 4 identical systems and the parts were all bought from the same supplier and at the same time. One of them just wouldn't stay up for more than an hour or two before it would reboot by itself. In the end by swapping components between the machines I found out that the CPU was just bad. Sent it back to be replaced and it's been working fine ever since.

- Trevor