Dawg, what are you using for BDP? It used to be a PS3, yeah? Whatever is doing the decoding, either Denon receiver, or player, you must disengage "DRC".
TrueHD tracks have what is called an autoflagged DRC. Normally, it shouldn't be this kind of issue, even though I still prefer it off with everything, The Dark Knight, you name it.
However, Iron Man is easily, by far,
the most infamously horrible implementation of this autoflagged DRC.
Disengage, try again.
The worst BD for hitting limits, so far that I have read (not heard, or seen), is Pulse. Lemme go see what the track is on there.
You can see here that I've brought up this particular movie's issue before. (I've brought it up many times, like in 20 threads, since it came out, what, 1.5 years ago?)
http://forums.audioholics.com/forums/showthread.php?p=477293#post477293