I have the Onkyo ht-r390, I route the hdmi out to the tv, a ps3 is plugged with hdmi on the bd/DVD channel and an xbox (original) is plugged into the coax, the xbox is using component to the tv (not thru amp). The problem is that no audio comes thru on the coax UNLESS I turn the ps3 on, then turn it off. This seems to force the amp to switch over to coax. As this is very annoying, anyone know how to stop this? Many thanks in advance.