I'll auto reply to myself, indedd, leaving it off kills the nigth mode.
But the funny part is this.
I enabled the DTS option, and used movies that actually had 1.5 Mbps tracks, like Superman Retunrs, Alexander, Enemy at the Gates, and such, and man, having that nigth thingy off, makes is sound brutal, BUT in DD. When I swich to DTS I get a more soft track, like if the nigth mode was on (wich is not).
Really weird, but after testing it, I 'll keep the DD option over the DTS (I have a Yamaha 6.1 A/V so I'm guessing is not that) and without the nigth mode on, I'm more than happy.
Silly, that after all this time, DTS doesn't meet with wht I wanted, but DD makes the trick.