Pardon me if this is the wrong section for USB issues; I didn't know where to post it.
Last week, I went to a client's house to fix a problem they were having with their USB. Whenever they'd plug in a USB device, regardless whether or not it was self-powered, there would be a windows notification saying that there is a power surge on that particular USB port and the device didn't work. From my own analysis, I've concluded that it is either a power supply problem or a SP2 problem. Any input? They'll be calling back any day now to get it fixed.