Hi, i am  having problems trying to get digital sound out of my Apple tv. I have HDMI from apple to Panasonic TV 2011 model, i have optic from TV to Yahama RAV312 amp. When i select auto my amp says it's PCM. When i select dolby digital i have no sound only works on PCM or Auto. If i then use my Panasonic 550 blueray player i can switch off audio from HDMI and i get dolby digital no worries at all. What am i missing here? any suggestions?