I've had it, I lack the time and patients to diagnose this myself.
Synptoms:
Random black outs and reboot during gaming (at first): Bolted 120mm fan to card, seemed to work at first, then failed, replaced card, seemed to work at first.
Then it started blacking out at more random times, during the night while downloading.
Replaced
PSU. Seemed to work at first, then failed, added 2x 80mm blowholes to the side of the case, worked at first then failed.
Next ideas?