I recently got the 3805 and a a similar problem. double check your input assignmants that was the cure for me. I ended up connecting my cablebox directly to the tv so I can watch tv without the speakers cranking up. Another thing I did that really made things easy for me was I knocked out the back panel of the entertainment center for easy access. it is still there hanging on by 2 screws.

M60's VP150 QS8's EP500 Denon3805