There are two major problems with the book. First the two lead male characters are far too old for the role. They have to be nearly 30 if they are anything, and that got in the way of the film. They didn't look young and their roles needed a young actor.
The second thing is that it's beyond predictable. We've seen this this a thousand times before, and this film bring nothing new to the scenario. So, in short, a really bad film. I think that Hayden Pannetierre was in it for they paycheck.