i just bought a 7900gtx and when i went to instlal it into my alienware case i encountered a problem. Where i am supposed to have the pci ports stick out of the back of the case (that little metal frame thingy with like 7 spaces) it wont let me install a dual slot card. There is a little metal arch thingy that prevents me from having the card go flush against the frame thingy and therfore instal it. Plz help