Can someone tell me if the WD HD TV media player outputs multi-channel audio through the optical output when playing video files with AC3 Dolby multi-channel audio (such as .mkv or .ts [h.264]). Some posts here and other documentation seem to say it does output multi-channel audio from AC3 but others seem to say it does not. Some seem to say multi-channel audio is output only through HDMI, which I cannot use. If multi-channel Dolby audio is downmixed to 2 channel, can you tell me if the mix is matrixed to be compatible with Dolby ProLogic (so that the receiver could decode and recover most of the original surround) or is it a simple stereo mix?