i have a mbp 2011 i7 2.0 i always use usb port (1) for my USB speakers. its always plugged in (1). Then all of a sudden music stopped working. i thought it was the speakers at first. so i troubleshooted to no avail. i restarted and nadda. i then tried using usb port (2) and the speakers worked again. so i thought usb port (1) is dead, but i plugged my external hd and recognized it. plugged my speakers again to (1) and speakers didnt work, so now the speakers only work on usb port (2). anything know whats wrong?