When I play lord of the rings 5.1 dolby my surround sound speakers work, when I play my Pirates of the Carribean 6.1 dolby I only hear the background sound but no voice and the same when I play The Weatherman 5.1 dolby. I have a toshiba dvd/vcr combo plyer hooked up to a JVC Stereo/tuner.
That is usually normal, though. The surround only puts out sound if the movie calls for it or if it is necessary to reflect the scene on the movie. It is there for background effects and if the person speaking is portrayed to be in the back and moving to the front. It would be weird if you can hear the person speaking all around you when they are supposed to be just up front.