BD Rebuilder best possible quality?

[sparkyar]

Hi, when encoding to BD25 why Im getting noticiable better quality with 1pass ABR than with 2 passes.
Im using highest (very slow).
Ive tried custom target and bd25, and the difference in size in the main movie is 300mb so it cant be that.
I want the best posible quality and I dont care about encoding time, I have to enable some hidden features or what?
thanks

BDREBUILDER.INI

[Options]
VERSION=0.37.0.7
MODE=0
ENCODE_QUALITY=3
ONEPASS_ENCODING=0
AUTO_QUALITY=0
QUICK_EXTRAS=0
TARGET_SIZE=26500
AUDIO_TO_KEEP=eng;spa;
SUBS_TO_KEEP=all
SD_CONVERT=0
OPEN_GOP=0
RESIZE_1080=0
DEINTERLACE=1
SD_TO_1080=0
CONVERT_WIDE=0
DTS_REENCODE=0
AC3_REENCODE=0
AC3_640=1
AC3_192=0
KEEP_HD_AUDIO=1
AVCHD=0
REMOVE_WORKFILES=0
MOVIE_ONLY_LOOP=1
REMOVE_OUTPUT=0
USE_FILTERS=0
BDMV_CERT_ONLY=0
USE_LAVF=0
IVTC_PULLDOWN=1
ASSUME_DVD_PAL=0
AUDIO_TRACK_LIMIT=0
SUBTITLE_TRACK_LIMIT=0
CUSTOM_TARGET_SIZE=24200
[Paths]

The scenes with dark areas get too pixelated

Sorry for my poor english, Im from Argentina

Great app btw