I can't select bitstream audio(Dolby Digital) for my cable box output. Everything is shown as two channel. If I select my DVD option I can get5.1 audio. What am I doing wrong. I'm getting prettyy good at fifuring the remote but can't find the right option. Going through the manual setup and sound menu and hdmishows v463. My guide says it should say htr-6140. Does any of this make sense?