I've been running my 3x7950's for a few months with no problems. Tonight, I had one of the cards out while I was working inside my case and decided to pull the heatsink off and apply some AS5. I've re-seated dozens of heatsinks without any problem, but not this time! Now, whenever I fire up cgminer, the temp monitor jumps to 500C on the re-seated card and then the system freezes and needs a hard reset. Any ideas about what I've done to the card? Tips for fixing it?