As mentioned, I brought the machine upstairs to work on, next to my Mac so I can hit the net at the same time.

I've removed the only two cards in it, both Hauppauge capture cards, removed the memory (Crucial dimms) and then re-installed the memory and booted the system to the MemTest.

Right now we're on the 4th test with no reported failures yet. The only other difference at this time is that I don't have the USB nor PS2 keyboards or mouse plugged in.