I see, that's what I thought too. Not a big deal, the OST itself is way more pleasant to listen to by itself. I'm actually one of the biggest 3.0 haters around here, but no way I could miss an Evangelion movie playing at a theater in my city!
@FreakyFilmFan4ever: Thanks for the tips, but I was talking about a real movie theater, and I'd expect one of these to be already calibrated by a professional...
Unfortunately I don't own a home surround set, I usually listen to movies and TV series with headphones. Less complaints from the neighbours and, well, a decent headphone (plus a cheap amp) is way cheaper than a good surround set.
I used to play with the mixdown settings for the best results, as you said (my player of choice, MPlayer, is pretty customizable in this regard even if the documentation is often a mess), but nowadays I simply go with the defaults, they're usually good enough for my ears.