I've got a problem when playing a DVD movie/disc through my Sony GX300? I've set-up the DVD player to a Yamaha 750SE amp & now when ever I play a DVD movie, I have to watch it through the amp & speakers & it won't allow me to watch it through the TV speakers. This is annoying, as if I want to watch something a little later, I have to turn the volume down low! (neighbours) Could anyone tell me what I have done wrong & help me get to a set-up where I can choose to watch/listen to a DVD through the TV or the amp/speakers??