Just curious, but I woke up this morning and the airport wasn't on. Upon checking the unit, there was no power indicator and the power brick was emitting a high pitch beep. The airport is plugged into a backup UPS w/ surge so I'm not sure what happened. I checked the outlets, plugged it into random ones and then into the wall. 10 minutes later it started back up, and I re-plugged it back into the UPS and its running fine.. Any ideas on why it shut down to begin with and not turn back on when plugged back in for 5-10 minutes?