Windows Random restarts with Serious Error Recovery message

I have had problems lately with my system randomly locking up then restarting and when windows loads up again, it gives me the message that says "The system has recovered from a serious errror". Also, for some reason about 2 weeks ago, my CPU temps jumped from around 40 to 52-53 constantly. I haven't changed anything, but here is my system so you can know what I am talking about.

ASUS A7N8X 2.0
Barton Mobile 3000 running 11.5 x 200, I have dropped it down from 12.5 to 12 and now this, thinking maybe thats what the stability problem was, but it ran great for a few months before this at 12.5x200
Zalman CNPS 7000 CU at full speed
Arctic Silver 5
2x512 pc3200 PQI turbo Ram at 2.5-3-3-7
6800 unlocked the extra shader and pipe with Riva Tuner
Zalman VF700 CU
SB Live! 5.1

Windows XP pro

This is getting increasingly annoying because it is happening more and more unfortunately. Any thoughts anybody?

 

Heat? Maybe reseating your HSF would help?