I am in the process of recoding my DVD's to .mp4 format with Nero Digital. Most movies work fine. However, some give me an error when I go to import the title saying that the the audio track is not supported by nero digital and will not be included. It allows me to continue, but the .mp4 file then does not play certain audio tracks.
For example, Ocean's Eleven, you can hear music and background noise but the main track with chracter voices is not there.