You shouldn't have to jump through hoops, upgrade BIOS, reinstall windows, etc... just to get a frickin' video card working.
Amen to that.
For all you folks who disable BIOS features or turn off fast writes or lower your AGP speed to AGP4X...
YOU ARE SETTLING FOR LESS THEN WHAT YOU PAID FOR
The 6600GT WORKS WITH AGP8X... IT WORKS WITH FASTWRITE... IT WORKS WITHOUT HAVING TO JUMP THROUGH HOOPS OR DISABLE BIOS OPTIONS.
If
your 6600GT doesn't work with the above features, and/or you have to turn them off to get stability at the cost of performance, YOU HAVE A BAD OR PARTIALLY BAD CARD AND YOU ARE SETTLING FOR LESS THEN YOU PAID FOR.
Why aren't you all RMAing your card to get one that works as it should?
dzadzi, I am convinced you have a bad (or partially bad) card. Something isn't right with it. RMA the sucker and be done with it... get another card. A GOOD card/chipset will run stable and fast right out of the box (assuming you have the proper drivers installed and plug in the power connector).
Stop jumping through hoops to get the card to work, and whatever you do, DON'T SETTLE AS OTHERS HAVE BY TURNING OFF SPEED FEATURES LIKE FAST WRITE OR SLOWING DOWN YOUR AGP BUS... the 6600GT DOES WORK with fast write and AGP8X, if it doesn't your card is screwy!
Just get another card. That's what I did, and my problems disapeared overnight with a new card.