New nvidia driver break my vidcard and bios or was it a coincidence ?

Heres my problem hope someone can help ... i downloaded the new nvidia drivers 195.62 WHQL (previous to this all was well) and after installing them my Graphics card Geforce 8800gt started displaying odd graphics , so i rebooted again and the post screen and the bios screen were all corrupted large green blocks , how can the bios be effected by a driver update . Anyways i was after a new Graphics Card so i decided to use this as an excuse and buy the BFG GTX OC2 MAXCORE 55NM..

After re-setting things back to normal and using an old card i had a 7800 .. my new BFG GTX OC2 MAXCORE 55NM arrived .. i installed the new drivers again after installing etc etc etc booted up the pc with my new 216 card and all was well for about 1 hour then again had the same problem glitching and short freeze up here and there so i rebooted . Straight away while still in the post screen view loads of little dots all over the screen and the text was all gobbledygook and messed up, i managed to enter the bios screen same there as well ? does anyone have any idea whats happening here ? as when i put my old old 7800 G card in everythings ok again . Is it my motherboard or did i just get a dodgy Graphics Card strange thing was all was well untill i installed those new drivers...

I removed the old drivers and rebooted etc etc before installing new one ..

My specs are PSU 850W
CPU Intel Q9650
2 Gig Ballistix Gaming RAM
Asus IP35 Pro

Thanks in advance

If you are overclocking the cpu/motherboard, make sure the PCIexpress bus is set at 100mhz.

Other than that, all I can think of is a potential heat problem. Cards overheating display the same artifacts as what you mentioned. How are the temps?