If Dish is anything like my cable provider, many channels only come through in Dolby 2.0 - I've even had the local affiliate (or cable company, not sure who's to blame) "downmix" Dolby 5.1 to Dolby 2.0 by simply stripping the left and right channels out, leaving out the center channel (and all of the dialog). Try enabling Pro Logic IIx with those Dolby 2.0 sources and see how that works for you.