Sounds like it fried them, as the controller ports on the XBOX are USB 1.1 (I think). Very odd though. Try cleaning the ports and leaving it off for a bit.
Not sure why it would do it. Did it blow out all 4 of them? That would indicate a bigger problem than ports.
It would have to be a problem with the actual USB chipset then. The ports themselves are two separate connections. Not that you couldnt replace the ports, thats easy, but it would be strange for them to work occasionally, and not at other times.
Maybe the daughterboard decided to come loose at the most opportunistic of times? Unless you don't have a daughterboard sporting XBox.
I'll pop it open sometime this weekend and check it out. I'll try to find my multimeter and see if anything seems amiss.
