The 7800gtx is a PC card that has a rom chip transplanted from a donor mac card, or so i was told by the guy who i bought it from in the states - though i read that a few months later he started ripping people off and not sending cards out after receiving payment, so it may not be true i suppose. The original card was the stock card available at the Quad 3 years ago when I bought it, and when i try to boot with the stock card, nine times out of ten i get vertical lines all along the screen, and only 25% is visible. It has booted without problems using either card on a couple of occasions, but most of the time it freaks out in one way or another. This is driving me mad - I can't believe that a 3 year old machine may need to be replaced!
Thanks
Matt
Do you mind my asking who you bought it from?
I think I might have been another victim.