Counter-Strike is KILLING me!!!

Everytime I play CS for about 2 hours (its addictive as hell) and hit ESC to get outta the game my pc reboots! What's going on?! My cpu temp is at 38ºC and case is at 34ºC but maybe it might be my PSU?? here's the voltage:
VCore Value = 1.76
2.5V = 2.62
3.3V = 3.43
5 V = 4.86 (is this a problem?!)
12 V = 12.07
my PSU = Enermax 431watts (i thought it was a good one )

well the rest of my specs are here if needed:
axp 1800+ w/ alpha pal8045 hs w/ delta fan (loud)
abit kg7 raid
512 pc2100 crucial
15gig seagate (boot)
geforce 3 ti200
Windows XP Pro
sound blaster live..

i think that's all there is needed to know..PLEASE HELP!!!

didnt have one of em electronic pens so ill just type my name,<i>CoOoLMaNX</i><P ID="edit"><FONT SIZE=-1><EM>Edited by CoOLMaNX on 05/24/02 02:24 AM.</EM></FONT></P>

meh just formatt... it fixes 98% of all problems, LOL.
Or you can try blaming Abit, but that's another story.

yeah temporary solution is just bring down console and type quit.

I dont know why it does this? I mean I have heard of system freezing because of the sudden resolution change but man a reboot, thats weird.

<b>If it aint broke, <font color=red> overclock </font color=red> it</b>.