I just got an Onkyo HT-S770 and am having a little bit of trouble selecting different surround modes. My dvd player is connected with an optical cable to my reciever. The problem is I can only switch between Dolby Pro Logic IIx Cinema/Music/Game and Dts Neo 6 Cinema/Music. I cant seem to switch to Dolby Digital which is what most of my dvds use. These are the only options I can switch between when selecting the listening mode. Any help would be appreciated.
THe owner's manual is sort of hard to use, but there's a section that addresses the receiver's defaults. You could likely go into one of the setup menus to tell the receiver to either always, never, or automatically switch to Dolby Digital. Mine's set to "auto" and seems to work. I also set it to auto-detect DTS as well.
On my DVD player, I had to tell it to send the digital signal through the optical connection. Check your DVD setup to see if the digital output is set to "raw" or "PCM" or some other name. I found my DVD was sending the analog signal through the optical out, which my receiver obviously couldn't use to make a 5.1, 6.1 or DTS soundfield, but it could use it to make sounds come out of the speakers.
Hope this helps, as I had almost the same problem...