I just stretched my feet out underneath my desk and just BARELY pulled the USB plug out of the back.  All of the sudden my mouse stops working, so I check the hub.  All the lights are off, even the power.  I take it and check the power cable, unplug it and plug it back in.  Nothing.  The power light blinks and then goes off.  So I think I have a bad power supply or something.  I get the hair-brained idea to check the USB cable and sure enough it's unplugged.  Plug it back in and all the lights come back on.  What kind of idiot designed the hub so that ALL the lights go off when the USB root gets unplugged?  The power light!?!  Leave it on!