It's not normal. Double check that the movie is outputting in Dolby 5.1, not 2.0. Let's see... to get it in Dolby Digital, press a lot of buttons until the display mysteriously changes to Dolby Digital. As I recall from a 3806, this is the Normal button. Err.... I was feeling at lot more helpful when I started this post than when I finished it.

I am the Doctor, and THIS... is my SPOON!