Sorry, I don't speak French and had to use an online translator to get the idea of your problem. There are 2 types of forced subtitle: 1. HD-DVD - they are known at the beginning and will be saved as xxx_FORCED.SUP. BDSup2Sub is called to convert all xxx.SUP to BD format xxx_EXT.SUP 2. Blu-Ray - they are embedded in the regular subtitles and only known after eac3to has run. you can see this in eac3to_pass3.log. if they exists BDSup2Sub is run to extract the forced out, and are stored in the format xxx_FORCED.SUP On the options screen you have a field for subtitle order: Now the .META file for tsMuxeR is rebuilt and based on the subtitle order all _FORCED.SUP (ord _FORCED_EXT.SUP) are now stored after audio, but before all other subtitles. If the 1st subtitle prefered language exists (probably FRENCH for you) so SUBTITLE_FRENCH_xx_FORCED.SUP then this will trigger auto force - ie changes the movieobject.bdmv. You can check the forced logic is working by the presence of files called _FORCED.SUP, and the order of the .META file is slightly different to the order you actually selected in pass3. Hopefully this makes it abit clearer for you. Perhaps someone can translate this too ?