LFE in the Dark Knight Rises issues

I have a question...My home theater set up is good(for my liking), and the sub works great...shakes the walls and house when I want it too.

For the new Batman movie, I really had my hopes up for the bass, and when I watched it, i was less than impressed. I just figured they must have laid back a bit in the mixing. But looking online and from what I hear, the bass is supposed to be the best ever.

I had watched the Dark Knight prior to watching Rises and the sub was working great. When I put Rises in, it was almost non-existant. What could the problem be? Bad DVD possibly? anyone else have similar issues? I purchased the DVD, not the Blu-Ray as most of my movies are DVD and have no issues with sound at all.

My setup consists of a Yamaha RXV2500 with 5.1 surrond using Klipsch speakers and Klipsch sub model RW-10.

I am at a loss and would really love for the bass to be there making the movie that much better.

thanks in advance for any ideas if there are any.

Steve

Ok, update. I took the DVD back and picked up the blu-ray. Huge difference in audio. I had no idea. I have never run into this issue before until this movie. Thanks!