DTS master 7.1 vs Dolby surround

[bsmooth]

I have a Panasonic DMP-BD85 and I have a HDMI cable to my display and a coaxial cable to my receiver, and i do get great Dolby digital with How to train your dragon, but I can't get it with Dances with Wolves. On the reciever is a display and it says Dolby Digital when I have surround sound. I do get it the Dragon movie but what i get with Dances is DTS, which should be the same as Dolbly digital, but it just doesn't sound the same, even though all the speaker icons on my receiver are lit up. the Bass just doesn't seem to be there with Dances, but it thunders in Dragon.
Heres the really weird part, everything sounds great with regular DVD's with Dolby digital, they all sound great, But when I started getting Blu-Ray discs everything seemed to change, they aren't the same as regular DVD's.
Man I'm confused !