My PS3 is connected to my home theater via Optical. My cable box is connected to the home theater via Coaxial. The sound comes in great through the home theater when I'm watching cable, but when I turn off the cable box and turn on the PS3, I get no sound. If I unplug the coaxial wire from the back of the home theater system, sound returns from the PS3, even after plugging it back in. It will stop working again once I turn my cable box on. What the heck is going on here and how do I resolve this?