The problem is not necessarily with your motherboard. Maybe you have a defective USB 3.0 card. Regardless of what the drive seems to be doing, it sounds like your USB 3.0 card is not working. Is there another computer you can try the card in?
I would be surprised if Asus would lift a finger to help you at this point. Their support forums are hardly active, and your motherboard is certainly long out of warranty. I suppose it couldn’t hurt to ask, although there shouldn’t be a compatibility issue. A PCI Express device is supposed to work in a PCI Express slot, end of story.
