We have a Sony KDL-46V5100 that we are connecting (along with a comcast connection). We have it hooked up with an HDMI, and have audio/video. WHen we use netflix/bluray, the left and right front speakers work. Otherwise, none of the others work. When we do the speaker layout, we do get sound from all of the speakers. Any ideas of what we are doing wrong/what we can/should try?

Thanks for any/all advice!