an ASUS board you say? See...people don't believe me but I'm telling you ASUS is going down the sh!t hole. I'm not gonna say this is EXACTLY the problem, but I THINK its your motherboard. I can't find the thread, but I just helped a guy out with a similar problem. He had an ASUS board and everytime he loaded in his geforceFX 5700 or 5200 whatever it was, it would freeze on him and crash. I had the exact same problem. I e-mailed ASUS and their taiwanese technician said and I quote:
"You need new card....some card not work with newer motherboards. Get card refund'
.....yeah needless to say I said a big F YOU to them, bought an MSI and the card ran like a champ.
Gomer...have you tried putting the card in someone elses PC and see if it worked? Are you Running WinXP by chance? If so, I think your ASUS board is the problem, because me, some other guy on here that I just helped out like yesterday, and now you are all having troubles installing a geforceFX card into an ASUS board.
ASUS SUCKS BALLS!! Regardless what everyone else says "ASUS is leading brand in mobos blah blah blah' screw them.
My FX 5700 would work in my friends no name 'AZZA' brand motherboard which was older than my ASUS and it worked fine. If you can try it in another computer that DOESNT have an ASUS board. It seems to me that ASUS and the FX series don't like each other.
EDIT: Heres that thread where the guy had similar problems
http://www.techist.com/showthread.php?s=&threadid=26450