I'm jumpin in' because I have this problem as well, I treid the adjustmens suggested by Intero, but it didn't work. The DVD appears to have sound when played in WMP but not if I play it in my dvd player. I believe the file i'm trying to convert has a .wav format audio, while the video is .mkv. I don't see any audio encoding option in my Express Burn. Hope you can help.