different soundtracks?

Hi. What a great great movie. I´ve just seen it today for the first time on dvd and cried as ever. However I noticed something quite strange: It was the first time I saw it in english since I´m from Spain and on Tv had to see it dubbed. I have always loved the great music in the chase scene between the 2 ships at the end of the movie, it has a great sense of adventure and it is also very uplifting. To my surprise as I was watching it in english that music was gone! There was music but completely different from that.So i tried and selected the spanish audio and there it was again the music I remembered so well!. Does anyone know the cause of this or noticed about it? I have a region 2 copy btw. Thanks!