When should it get enough, if EVER?

[RabeaticSquirrel]

Ok, so the machine is running a T'Bird 800 (this is not my system, I learned my lesson) @997 via 105FSB x 9.5 x 1.85v. We've got it running seti@home, burnBX, CPU torture, and playing an MP3 using winamp in the background. It's cruising at 42.9 - 43.4 C. Doesn't seem to have any probs, but it did lockup after about an hour or so of running that topology. I rebooted and set the RAM to 100 MHz at CAS3. It's been running the same topology as above for about an hour. How long should it essentially run under that much of a load before failure? That is a pretty hefty load. Should we expect any failures at all or should it run forever?