Subtitle extraction problem

I tried AnyDVD with Nero Recode on The Two Tower. It works fine. However, when I do the same trick to The Return of the King Extened Edition, subtitle extraction failed. I can’t select the subtitle. In fact, no subtitle menu was shown up. It has only video, audio and info. When I backup The Two Towers, there are four menus, i.e. video, audio, subtitle, and info. I wonder is this a problem with AnyDVD or Nero Recode. Any suggestion?