When I rip a DVD to my home computer I have no problem watching it. However, if I rip a dvd to a flash drive the movie comes up as unplayable. The message reads: 'Can't play. The file isn't playable. That might be becausethe file type is unsupported, the file extension is incorrect, or the file is corrupt.' I am saving the file as a mp4 file. Again it plays on my home computer but not from the flash drive. Any suggestions?