I'm not sure if it's DTV, the Nat Geo network, or specific shows, but I've noticed with a lot of the National Geographic content the audio quality of those being interviewed will be horribly weak, and possibly only coming out of surround speakers, but as soon as the documentary voice over starts that audio will be booming loud out of the center channel. I am constantly adjusting the volume up and down because of this... Or at least I was, I've just stopped watching all together now. Any idea where the problem lies here? Commercial volume, although loud, is consistent. Maybe it's the programming itself?