I wouldn't have believed this unless I saw it w/ my own eyes. Spent part of the afternoon @ a friends house diagnosing an apparent overheating problem. Cpu (Duron®) temp was a nominal 45°C but the screen would go black, off & on, sometimes reappearing in a small resolution. When I arrived the case was off w/ a desk fan blowing cold air. Another fan was blowing on the monitor. Even then I witnessed this black-out problem. We decided to strip down the rig, vacumn, clean, & applying ASII to the HSF, a FOB32-1 4200rpm. Upon restarting we watched the hardware monitor & the problem reoccurred in about 5 minutes, even thought the temps were w/i limits. Observing w/ a flashlight I noticed the Voodoo5 ( a full size card) was vibrating. Holding it steady solved the problem. The vibration?! The clue was the hardware monitor. Fan speed was in excess of 4700 rpm. The cpu fan was backwards, blowing outward. Although this shouldn't effect the cooling, the over revving fan caused just enough vibration to make the V5 shake. We fabricated a bracket & attached w/ an insulating washer to an existing hole in the card, & to the case. Now we're steady freddy, but that was a weird thing to witness.