The cold CPU temp of 60°c bothers me, Thats still pretty hot, and is more than likely whats causing your crashing. I'm sure SISSandra has given you a warnig about that. Try running sandra's performance tuneup and see if it doesn't say something about getting a high reading between the cpu and the hsf. My xp2200+ and my 1800 duron never exceed 45°c during sandra multimedia benchmark, and 3d mark. Sounds to me like you need some more cooling or some better heatsink compound. Have you tried it with your side cover off?
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