ARMA2 CO Odd crashing after 5 mins

[janizki 10]

Okay so my system spec is the following:

Asus P6T v2 deluxe with i7 930(no over clocking exept fact. turbo option) (noctua NHD14 cooler(that massive one))

ATI 5870 (accelero actic cooler installes(load temps well below 50 on any game so far)(no overclocking since I did not find any usable OC without instability issues)

8gb RAM at 2133

(if more needed please do say)

And my problem is that whenever i play on chernarus(other maps last longer before doing it but chernarus is the worst) within 5 minutes of playing my game freezes gives the video card stopped responding message and when i try to return to the game i can hear the ingame sounds and can "play" the game or atleast I can hear the sounds of opening and closing the inventory etc. But when i get back into the game the screen is white and will not refresh and no matter what i try the screen will not unfreeze and i have to alt f4 the game.

Now ARMA 2 is the only game this happens to me in, Crysis 2/3 BF3/4 etc the games are as smooth as possible and the are no signs of crashing or freezing...anything like this.

Does anyone have a solution to this or anything to help me out....i want to play DAYZ but 5 minutes at a time kind of ruins doing anything...