Hello Dave.
The DRC thing is very simple. Some audio tracks, specifically of the TrueHD kind, have a "flag" that is automatically turning on your DRC. Iron Man, for instance, is doing it to your PS3 as well, whether you knew that or not.
Its totally lame. I know, I know. If you select TrueHD (but bitstreamed), you'll simply have to hit "Late Night" on the Integra, you will see "Auto", and keep clicking the late night button until it says off. So, it appears the DRC flag basically happens wherever your decoding is taking place. With a PS3, its obviously in the player (can't bitstream), for instance.
Regarding your other post in the other thread, I'm about to fire up the HT, and will look at my own BD-30 settings. Its pretty strange you can't get audio yet.
j