Did you overclock your cpu? Also, I'm just making sure, but how did you disable your bluetooth? Was it through your OS device manager, or did you disable it in your BIOS. When I had this problem, disabling through device manager did not mitigate my problem...it was only when I disabled it through BIOS that it worked. Here's the link: http://www.tomshardware.com/forum/forum2.php?config=tomshardwareus.inc&cat=30&post=311753&page=1&p=1&sondage=0&owntopic=1&trash=0&trash_post=0&print=0&numreponse=0"e_only=0&new=0&nojs=0
Try uninstalling your chipset's enhanced host controller. When prompted, do not delete software. And it will reinstall upon restart. Also check for the newest USB drivers on the ASUS support website for your particular mobo model.
If none of these works, then I'm stumped and I'm sorry I couldn't help you. Unfortunately, it may mean you still have a defective mobo...sorry bro