I encountered an Indigo slot-loading iMac this weekend which made an odd beeping noise while it was sleeping. It was sort of a high-pitched sound, and was definitely coming from the computer itself and not the speakers at all. Also, while the sleep light was "breathing," it would flash quickly with each beep, though the breathing and beeping were not in unison. It's really annoying. Has anyone encountered this before? Is there a fix for it?