Right. Simple question I hope. I have a PC with DVD player, Avance '97 soundcard (I think that's what it's called). GeForce 4 Ti4400 (It's also used to play games). Anyway I've got the system set-up as far as playing DVDs through my projector is concerned (powerstrip used to get the right resolution). However my amp plays the sound but is only picking it up as Dolby Pro Logic. Does anyone know why? and more importantly how I would get it to output Dolby Digital or DTS? It's plugged into the amp with a fibre optic cable.