Continuity: The phone number Sara writes on Jonathan's back is different than the one she writes in the book. (Time)

Factual error: Jonathan is lying in the middle of the skating rink when the second cashmere glove falls upon him. Looking around, he notices Sarah at the edge of the rink. Despite Sarah being a female and the fact that it is snowing, even Nolan Ryan would have a difficult time throwing something as light as cashmere that distance. (Time)

Continuity: In one of the ice skating rink scenes, the camera looks at John Cusack and there is no snow falling. It then cuts to Kate Beckinsale and it is snowing heavily. (Time)

Continuity: Towards the end of the movie, Sara (Kate Beckinsale) runs to the Waldorf-Astoria to stop Jonathon's (John Cusack) wedding. The first time she turns to leave the room where the wedding was to be held, she has just a few drops of sweat showing through her blouse. The second time she turns to leave the room, her back is drenched in sweat. (Time)

Visible crew/equipment: In the opening shot, as the camera moves down the building, in the windows you can clearly see the cameraman & camera on the hoist/crane. (Time)