In article > ,
says...
> Without the hard lock Id lean towards a driver issue. Onboard sound? Maybe
> reduce the acceleration of the sound hdw? Id try out a few different
> video/sound drivers and configurations (with w/o AA/AF) as well. Do you
> use the 4in1 drivers?
>
>

It's a nForce2 motherboard, so I don't think the 4-in-1's will be very
compatible.

Before I posted my original message:

I tried new Omega drivers. Same problem.
I tried new ATI Catalyst drivers. Same problem.
I tried a new power supply. Same problem.
I tried a larger heatsink on the CPU. Same Problem.
I tried backing the sound acceleration off one tick. Same problem.
I tried a Radeon 9700 Pro. Same problem (but a bit noisier due to the
fan).

The problem was the memory. I originally buit the machine to be a race
server, so it didn't need to have top-notch quality name-brand memory
because there was no 3D graphics load on it. It ran fine with the
budget PC2700 memory with an AMD XP1900 and then an AMD 2400 while
racing, but putting the 3000 in pushed the memory into instability. I
had 512mb of Corsair XMS laying around, so I tried it and the crashes
are now completely gone (not to mention the machine is noticeably
faster).