The Star Wars and the Revenge of the Sith version does not start off as the one in the movie. If you remember, the one in the movie starts off with battle drums, then it goes into the battle music.
The one on the soundtrack goes right into the song, and it really detracts from the value of the song. If you remember that all Star Wars opening songs finish off with that trailing piece, very soft, then it goes into the main theme, or a shuttle engine, or something. It just seems very weird to jump into the battle.