Just recieved a new Showcenter 200, got it all setup and working nicely. Only problem is no sound at all comes from the digital out coax or optical outputs. If I play something with Dolby Digital, the Amp lights up as AC3 audio, so it is getting some sort of signal - however that is simple it - nothing else happens. The audio does still come out of the TV if I turn the volume up though. Any ideas what I need to do??