transcode: unrecognized option '--use_rgb'

Another thing I observed. When I apply an asymmetric clipping (here 57 
top, 55 bottom) and ignore the red exclamation below the right preview 
window mark I get the following error when I click the transcode button:

Job 'Video Transkodieren - Titel #3, Lauf 1' failed with error message:
Command exits with failure code:
Command: mkdir -m 0775 -p '/home/raphael/dvdrip-data/ketten/tmp' &&
cd /home/raphael/dvdrip-data/ketten/tmp &&
mkdir -p /home/raphael/dvdrip-data/ketten/avi/003 && execflow -n 19
transcode -H 10 -a 0 -x vob,null -i
\/home\/raphael\/dvdrip\-data\/ketten\/vob\/003\/ -w 1983,50 -F h264 -b
128,0,2 -s 2.133 --a52_drc_off --use_rgb -k  -f 25.000 -Y
57,12,55,4 --export_par 106,100 -R 1 -y
ffmpeg,null -o /dev/null --progress_meter 2 --progress_rate 25 && cp
x264_2pass.log divx4.log && echo EXECFLOW_OK

Output: transcode: unrecognized option '--use_rgb'
'transcode -h | more' shows a list of available command line options.