No sound after joining vob files?

i was using "JoinVobFiles" software for joining vob files.now i am facing some problems with them.when i joining a movie notebook(malayalam movie) there is no sound.also another movie had the same problem.but i joined some movies with no problems.source video had sound after joining there is no sound.what i do?please help me?i was used handbrake software for ripping this movie but it becomes unplayable i thought this video was protected from ripping.please help me?