I'm unsure on how that works considering I bought it second hand
well next time don't buy new tech from a place like ebay where you have dodgy characters.
Even if you have a high end GTX 590 running in an x16 1.x slot, you should be fine to run it...just that you'd experience low frame rates because of the LGA 775 proc. but it'd still give you display.
Listen to mosox
contact the seller. If he ain't recieving the call, he knew the card was defective.
my 2 cents, hope this helps