I have a Denon AVR-688 receiver and a multisystem Panasonic DVD player. I have HDMI to my plasma and an optical to my Denon. NO sound. I have read the book a million times for both. I have gone thru the settings on the DVD player and I have turned the audio section to pass thru optical. I have turned volume off on TV. Still no sound I have configured the Denon and it recognizes a optical cable is in the slot but still no sound. Could there possibly be a conflict between the 2? Anyone please help. C&G