Topic says it all. I have my Xbox 360 connected via optical cable, the red and white analog audio cables are not plugged in, and the Xbox 360 is set to digital 5.1 output. When I test the tone on the receiver, watch movies, or watch analog or digital TV, the center speaker works perfectly. I've gone through all of my receiver settings and cannot find a solution. I've even tried using the 2nd digital optical port in the back to no avail. I'm about ready to pull my hair out with this because I remember it working at one point but just yesterday, I discovered that there was no sound from the center.
Does anyone have any ideas or things I may have overlooked?
PS. When I set the Xbox 360 to digital stereo, I get center sound again.