I am trying to get auto detected Dolby D signal from my SKY HD box. I have set up with HDMI and optical cables and set the audio output from the Sky box to Dolby digital as directed. The Yamaha manual leads me to believe that the DD signal will be auto detected and processed via the "STRAIGHT" function but the only way I can get surround sound is via the "SURROUND DECODE" function. I have made various adjustments to the input menu without success and if I select the "AUDIO SELECT" in the "COAX/OPT" mode i get no sound. Any ideas please on where I am going wrong?