I've noticed a couple of weird things happening with the optical audio output on my new 2009 Mac mini. The first thing I've noticed is that my receiver will stop displaying a PCM signal after a while (when no audio is present). It is as if there is a new energy saving feature to disable the optical audio when not in use. Sending an audio signal does not always wake it up, however, and I am forced to reboot to get audio working again. In more severe cases, the entire audio device acts as though it is missing. I cannot affect the audio out via the system preferences and the volume control on the menu bar goes missing! Rebooting again fixes the problem. With my late 2007 Mac Mini, my receiver always displayed a constant signal being received from the Mac regardless if audio is playing through or not. It never dropped off. Anyone else seeing this with their new Mac Mini? In addition to this problem, I am also having problems with Bluetooth devices not staying connected. I read this being reported elsewhere. Hopefully a firmware fix is on the way.