Uh oh.....if so, I hope we're talking about a piece of USB attached hardware.
That is easy enough to prove or disprove. Simply disconnect all USB devices, including USB hubs, and see if the problem goes away. If it does go away then start swapping out the USB devices beginning with the least expensive, the USB cables, going from there to any hubs, and keep going until the only thing left is the logric board. If Hal's "Hmm" is on target, and it sounds reasonable to me, this type of error is notoriously hard to pin down so have patience.
