Apologies if this has been asked a billion times - I couldn't find the answer... I've downloaded the "to the limit" Windows hi-def demo but when I play it back via PowerDVD6, or WMP10 or Windows Media Centre I can't get output via S/PDIF. I'm only getting a faint 2-channel output from the M-audio playing the hi-def source. I'm got an M-Audio Revolution 5.1 sound, Sapphire Radeon 9600XT Ultimate ATI graphics on an ASUS P4P800-VM board. Normal DVD's output DTS/DD via the S/PDIF fine with PowerDVD and Media Centre... Can anyone point me in the right direction?