The first movie I popped into my DVD player, since I wanted to try out the 6.1 audio, was the Lord of the Rings Extended Edition DVD. To my great disappointment, no audio at all came out at the DTS ES 6.1 setting.
The home theatre works perfectly if I set the movie to DTS EX 5.1 or with any other 5.1 audio movie.
If your unit has an "Auto-Detect" mode, set it to that and let the receiver do the job. If you switch mannually to 6.1 discrete, the unit is probably using the analog inputs.
The problem was with the settings on my DVD player. Apparently Samsung thinks most people won't be decoding DTS signals so they had all the settings for it off. I had enabled DTS on my DVD player but still had "PCM" instead of "Bitstream" as the digital out because I wasn't sure what it was. PCM only allows for 2 channel audio output.
I thought I was hearing 5.1 because the reciever has these nifty Dolby Pro Logic decoders that turn 2 channel audio into 5.1/6.1, but they aren't really what's encoded into the DVD. By setting the movie to DTS ES, without being able to output the signal from the player, I got no sound at all.
Yup, always read the manual for reference even if it's complicated. Seasoned users follow the basic set up troubleshooting guides by going thru the steps. That's the first thing that pops in my mind is dvd menu set up when the surround aren't activating because this happens to me whenever i set up a system or get a new dvd player. The pioneer has the mcacc auto pink noise adjuster to balance the surrounds, yamaha has the yao, sony has their version and others have similar auto detect and balancing to check if all surrounds are working. You're problem is a common problem regarding dvd or receiver setup!