I spent a whole afternoon perfecting the bassline to 'The Seeker' by The Who, only to find that the drummer was playing something completely different to the original version, when I asked him he said it wasnt important to play it to the record.
This caused a complete racket as the bass and drums clashed, so I had to play 4 to the bar instead.
So the moral is, if you have to play it note for note, make sure your drummer does too!