Thanx for the swift reply.
I`ve already tried to convert mp3 to .wav and .aiff with a different bit rate and sample rate, and it seems that nothing can compensate 8 seconds difference. Even the stretch tool in audition didn`t help, and although beginning and the end of the score match, everything in between doesn`t.
It was played from a laptop with iTunes and I`m wondering if the player somehow modified the duration of the score. I`d like to eliminate this option right out, but there is a possibility. It`s the same file I`m using in premiere and it`s the first time I`m experiencing a situation like this one.