I need help setting up my new Yamaha RX-V461 receiver. I've tried 2 different DVD players (both with 5.1 capability and coax digital audio outputs) as "DVD input" sources for the receiver. The Yamaha front-panel input icons consistently show only 2-channel (FL/FR) instead of 5.1 input icons. Sound comes through via DVD so (new, orange) coax digital audio cable is fine. I've tried full power shut-down on the receiver, plus factory setting reset. Yamaha tech support isn't replying to my "help" email. Any advice??