I just downloaded HandBrake to copy my kids' movies to the iPad and it doesn't seem to be working correctly.... As soon as I click on the source (the DVD), it starts processing and all the other buttons gray out so I can't select titles, chapter, destination file, etc, as instructed. It whirs along and says it's processing titles for about 45 minutes, then spontaneously stops and closes the program. No copy of the movie anywhere, and when I re-open HandBrake, it starts fresh with no record of having transferred anything. Any ideas??