Recent problems converting video to audio

[oolongblue]

Up until a couple of days ago, I had no problem whatsoever converting .flv and .mp4 video files into .mp3 music files, using a version of the VLC media player that I downloaded on April 1, 2010. Just recently, converted audio files turned out garbled, so I tried updating to the latest version of the player, which I downloaded today (01/04/2011). But this player doesn't seem to do any conversion at all. It has all of the same commands, but when I hit the final button to make the conversion, no new file is created. Can anyone tell me either how to get the new version to work, or what might have happened to the old one (which I presume I can restore)?
Appreciatively,
oolongblue