Force Dolby Digital --> Dolby Digital EX? Force DTS --> DTS-ES Matrix? Should you make your receiver force Dolby EX or DTS-ES Matrix sound out of regular 5.1 encodings like Dolby 5.1 and DTS? I have a 6.1 setup right now, but from what I've read before, it's best to just leave it on "Auto" detect, so that only movies programmed for Dolby EX or DTS ES play the sound from the 6th speaker. But I'm starting to read differently. For example, many of the DVD reviews on DVDfile.com say "If you have EX, use it." I want to get a lot of feedback on this, to finally get it decided what set our receivers at.