This has been bugging me for a while. How come on some shows like Smallville, the audio is encoded as stereo, but on others like Buffy they are encoded as dolby prologic. Everytime I watch Smallville I have to manually adjust the audio output on my receiver to prologic, but on the buffy dvd's it's automatic. Everytime I skip ahead in an episode on my Smallville dvds the audio shifts back to stereo so I have to manually adjust my receiver again... Is it just how the show elements were created originally? I personally prefer prologic because it seems to sound more "natural"