The 7.1 track is a little quiet, it could be because I only have a 2.0 setup... I have this problem with some movies, but cranking up the volume takes care of it.
I'm glad someone else said something about this. It seems EXTREMELY quiet. I had to turn up my surround receiver a full 15 points higher than I do any other blu-ray I own. I've noticed that in general, I have to turn up DVDs higher than blu-ray to get the same level of volume out of them - but this is the first time I've had to turn up a blu-ray so far.