Stop 0x00000101 "A clock interrupt was not received on a secondary processor within the allocated time interval"

This crash happens randomly. It's not temperature dependent, as it happens cool days and warm. The system isn't working hard cpu utilization is about 15%. This only seems to happen when I'm not around and the system is just running Folding at Home, Kaspersky AV, and Windows. ASUS P6T Delux, I7-920, 6GB OCZ Platinum, PC Power & Cooling 750 ps, Hauppauge 150 TV Tuner card, Creative Soundblaster X-Fi Titanium, Sapphire 4870. All drivers are up to date, BIOS just updated to 1701.  The system is overclocked, to BCLK 170 instead of 133. CPU voltage is 1.2, temperatures run 40-60. I stress tested running Pime95 without problems. I haven't found much online that seems to help. I have run both Memtest and the Windows memory diagnostic for a couple of hours each without any errors coming up. Thanks.