I heard rumours about the last OSX update causing problems with HDMI audio about a week ago, but didn't really think much of it, as as far as I was aware my late 2010 Mac Mini was running plex fine with no audio problems. That is until today. Now every time I try to watch something with a stereo or mono soundtrack I get no audio at all. Rebooting the machine and starting again seems to rectify the problem, but as soon as you run anything in either Dolby Digital or DTS through it, mono and stereo disappear again. Is anyone else having this problem?