Yeah Edwin, the Denon manual makes a valiant effort to conceal the fact, but read the notes carefully(if you can't find it I'll point it out)and you'll see that when there's only one back surround speaker the DPLIIx Cinema can't be applied, since the effect needs two. As was said, use the DPLIIx Music, which also does a good job extracting the rear surround information from the sides and sending it to to the back where it belongs, although of course the one speaker can't give the stereo back surround.
