Usually romantic comedy movies like this have the problem of the actors being way too old for their roles. Adam Brody has the opposite problem; he looks like he blends in with the high schoolers around him and it's tough to picture him as a 26-year old (even if he actually is).
The movie also compounds the problem by not giving us enough motivation behind anything Brody's character does. The movie has a few "nice/interesting/cute" moments but mainly, like the family of blondes across the street (who do admittedly carry the show), the film suffers from a lack of depth.
-Ripe Tomatoes-