Just lately my system will have an audio distortion. It will happen on my my satelite feeds and if I change the channel it will come back to normal. I have a Denon 4802R receiver that is feed by the optical input. The system is about 2 months old. I have read the threads on audio dropout but this is a distortion not a dropout. I have not tried pulling the card on the receiver and resetting the unit. Any suggestions what the problem is?