I recently converted a long movie (3 hours 25 minutes) to PS3 (.mp4) format. The audio was 5.1. On playing back the converted movie, I found that the sound suddenly stopped after about 3 hours. I know that the source DVD has sound beyond 3 hours. I tried converting again but same results. Is this a known issue?

Fair Use Wizard 2.8 on Vista.

Thanks

Update: I checked the intermediate audio files. Fair Use creates .ac3, .wav and .aac files. The ac3 and wav files have complete audio but the aac file has the audio cut off. I tested on couple of movies and audio cuts off exactly at 3 hours 6 minutes and 30 seconds.