Hi, I did a lot of research, and learned that the only way that I can output true 5.1 surround sound to my home theater system is in several applications like DVD Player and VLC Player. I have no problem outputting 5.1 sound in VLC, but I can't get DVD Player to work. From what I gathered, I need to go the Preferences in DVD Player, and under Disc Setup, I need to change Audio Output to Digital Out so that DVD Player will not mess with the audio format and pass it down to the home theater system. However, it's set to System Sound Output and it's greyed out. I tried to re-launch the application but no luck. I also verified in System Preferences, Sound, it does show that output is Digital Out. Does anyone have any idea? When a movie in DVD Player, my receiver shows the signal as PCM. Playing the same movie in VLC, the receiver displays the source as Dolby Digital. Any help would be greatly appreciated. Thank you.