Waterworld - unused Mark Isham score

While digging through my loft looking for a couple of CDs I came across a poster for "Waterworld" (one of those promo ones you can pick up for free at the cinema), which credited the music to Mark Isham. Obviously, James Newton Howard got the gig in the end, but what happened to Isham's score? Was it rejected by the studio/Kevin Reynolds? Has anyone ever heard it to compare to Howard's score? I'm asking out of curiousity - don't get me wrong, I love Howard's version - but it would be interesting to know what happened.

bentleyjames52, August 16, 2004; 8:10 PM