6870 display driver has error every 3 mins

Ok so i rma'ed my r6870 hawk and the new one they sent keeps giving me the (display driver stopped responding and has recovered) error every time a start a game and if i try browsing the web or anything on the desktop it give me the error every
2 to 5 mins my computer freezes then in 3 to 6 sec the screen blinks and the error comes up any ideas.

i have tried fresh install of windows 7
newest motherboard bios
older display drivers
reseating the card 3 or so times
graphics card bios update they where the newest available
installed the newest chipset drivers
and many other things i can't remember

i have no other computer to test with
but my other card worked for a while and played threw battlefield 3 single player 6 to 7 hours
and lots of internet browsing with out ever having the display driver error

system secs
gigabyte MA785GMT-UD2H
Athlon II X3 440
western digital black 500gb sata
G.SKILL 2GB 2 x 1GB DDR3 1600
corsair cx400
dvd cd burner combo ide
front case fan 80mm
rear case fan 120mm
random gateway case from really old computer.

they both say we did not detect any problems and therefore no fixes were applied

sound like it could be the case but why did my first one work and never have display driver errors

and why dose browsing the internet make it crash but stressing the gpu to 100% in a game dosent.

no just vlc player but i tryed the card before installing anything and it did the same thing its doing now.
where did you come up with a 6870 hawk needing 38amps

there is no such option in my bios or i would try it