just to add my name to the hat here
my XBOX 360 (it is the Halo edition one with HDMI) does not want to pass Dolby Digital
My HDTV set supports Dolby Digital alone and should show up as dolby digital but does not. In addition going HDMI in to the HDTV, then coaxial digital out to my receiver I do not get dolby digital
This works fine with my HTPC and my PS3. the PS3 also will pass DTS which my TV doesnt know what to do with it but it ends up at my receiver just fine.
so far the only time I have been able to hear Dolby Digital from my Xbox 360 is to use optical straight to my receiver
, it wouldn;t be ushc a big deal if I could turn off HDMI audio all together as then I can set the reciever to auto change to whatever input has sound on it. Then when I swithc to the 360 on my TV it would swithc to the 360 on the reciever, and when i switch back to my HTPC or PS3 and it senses the audio on that input it would change back.