I did a search and found thishttp://vip.asus.com/forum/view.aspx?board_id=1&model=Striker+Extreme&id=20081224003855987&page=1&SLanguage=en-us
"PCIx version 2.0 cards are backward compatible with version 1.0, so this should definitely not be an issue. In some cases the video card's installed BIOS may be incompatible with certain motherboards. In this case you can get a BIOS revision for the video card from the card manufaturer that will fix this and you will need to install the video card on a machine that is supported long enough to flash the video card BIOS. Call the manufacturer and ask them specifically about the video card BIOS being incompatible with your motherboard. If they say there is no known issue then make sure that your PSU supports the video card, and if so then you're home free."
So try updating the VGA's BIOS and check if it helps(it's risky though,but its the last thing i can think of).