As JP1 DTS soundtrack was right - but done using a previous setup, as my HD was "accidentally formated" (oO_), I've done another conversion, just to see if my present software setup is faulty... but everything was OK, so... there is some faulty cables (I used the same optical one for both captures), or JP2 DTS laserdisc has some glitches, or the last time I used CLD-D925 to capture DTS (this last thing I don't remember clearly, as I've done so many captures for both JP1 and JP2...)
Tomorrow I'll capture again the DTS laserdiscs, using the D925 this time, or the 909 with a coaxial cable instead the optical one; I'll write here the conclusions (positive, I hope).