Random crashing - extremely often

[Aerycat]

For the sake of testing
I've lowered all the settings on graphics by 1 level on each option and the got a GPU temp log as well. It crashed on me after about less than 20 minutes. My GPU temp maxed at 76.5c when it happened and fan is constant at 30%. All the while my CPU temp never exceeded 65c.

Last reading on GPU-Z log
Date 2011-08-05 23:29:05
GPU Core Clock [MHz] 830.0
GPU Memory Clock [MHz] 1250.0
GPU Temperature [ｰC] 72.0
Fan Speed [%] 30
GPU Load [%] 64
Fan Speed [RPM] 2198
GPU Temp. #1 [ｰC] 72.5
GPU Temp. #2 [ｰC] 74.5
GPU Temp. #3 [ｰC] 76.5
VDDC [V] 1.1200
VReg Temperature [ｰC] 64.7

..... no, not temp issue...