Chaintech 6600GT PCI-E restarts pc?

[Boomslang]

Is it possible for a display card to restart a pc? My setup is the following:
AMD Athlon 64 socket 939 3000+, MSI Radeon express RS480M2 Motherboard, 1024 MB DDR400, 450W Antec PSU and then the Chaintech 6600GT PCI-E display card. I've swopped out the PSU and RAM. I've tested the motherboard on another system and ran 3dmark2003 non stop through the night without restarts. what happens is if you play a game that taxes the computer it will hang and then restart. I have installed enough cooling and even replaced the thermal paste on the cpu cooler.
Ive noticed that the 6600gt runs very hot compared to my 6800 Leadtek card.is it possible for a display card to overheat without being OCed?

 

[apache_lives]

my Prolink 6600GT AGP overheated and locked up my system in battlefield 2 when hitting temps above 92 until i got a decent cooler and that fixed it.

Infact the new cooler (zalman 7700cu?) at max ran colder then the stock cooler at idle (~65's).

Id say its a posibility - check the thermalpaste on ur video card btw.