ALSO, have you overclocked this card at all? Do you have sufficient case airflow? What kind of cooler is on the video card? is the fan on the card running? I had an issue way back when i had a 5600FX and the fan died and it would lock up after a while. How far into the game is it that it locks up?
it freezes during battlefield Vietnam and Battle field 2 also during command and conquer generals. i have a zalman cooler (mid range). Bf2 freezes about every 15 minutes or so less with Vietnam about every 25 minutes or so.C and C it freezes on the menu the only game to do that.i have no over clocked the card. the weird thing is that sounds will repeat while freeze occurs. the freeze is about 15 seconds but never does crash the game. i have low temps of about 52 degrees celcius during game play. my system temp is also low. I don't believe over heating is a problem. My psu is 480 watts with two +12amp rails of 16 and 18