i think there is usually problems with the mp3 and mpg2 plugins when upgrading nero . i tried mpeg 2 1.2 with nero 5569 and and when i went to code the movie fiel it gave me a little advertisement message to buy the plugin even though I already installed it .
i could tell you how to use allways the latest mp3 plugin (unlimited encoding,Kind of) but that would't be fair play.please support ahead and buy the plugin and if you have any problem contact ahead! I'm sure they will help you.