Yes I have the latest drivers, and I hope my card isn't overheating, I'm running all fans at max in an attempt to keep it as cool as possible...I have a new card coming so we shall see if that fixes it
I posted this in another Tom's forum message but hopefully it will resolve your issue too with the 5770.
I believe I have finally resolved the GSOD on my system.
Win 7 - 64
2 x Gigabyte HD 5870 in Crossfire
I underclocked the GPU clock to 750 MHz (default is 850) and the Memory clock to 1100 MHz (default 1200).
Since doing this I have not had any GSOD which I would get within minutes of playing Left for Dead 2 and BF2 Bad Company and I can now play for as long as I want without problem. It has been over a week since I did this.
I have not flashed the card(s) bios so it is still on the original version and the Catalyst drivers in use are 12.4. I have had GSOD with Catalyst drivers all the way back to 10.9.
I know I have majorly underclocked the cards but my PC is stable now. I may try incremental increases in MHz
but to be honest I have had the GSOD for so long, now it is gone I can't be bothered.
Anyway maybe it is worth a try.