I have my xbox connected to my pioneer Pioneer VSX-AX5i using the optical input for dolby digital sound. I have assigned the optical sound to the VCR button on the remote. I have phone leads coming from Tivo into the TV audio phono connections on the amplifier. When I am watching the Tivo, the sound of the Tivo is coming through fine. When I switch the xbox on I can hear the sound of the xbox at a lower volume also. Is this a fault of the amplifier or have I configured something wrong?