I have a 17" 2010 Macbook Pro with a Mini Displayport that allows both audio and video, and I've set it up to connect via HDMI to my Dynex HDTV, which has an optical audio connection to a Panasonic 7.1 surround sound system. My TV works fine with 7.1 audio on everything else, and I've gotten video and 2-channel audio to work on the surround sound, but I can't set it up to do anything more than stereo. It seems to be a software roadblock in Audio MIDI Setup (screenshot below). Any suggestions?
2010 MBP-->MDP-->HDMI-->HDTV-->Optical Audio-->7.1 Surround receiver
2010 MBP-->MDP-->HDMI-->HDTV-->Optical Audio-->7.1 Surround receiver