When shot from the outside, Paul's apartment has windows that are mullioned into four sections (two above the sash, two below). When shot from the inside, however, the windows are mullioned into six sections (three above the sash, three below).
When Connie first goes to bed with Edward, while he's testing his camcorder there is several boxes on the bed. A minute later they are all gone but it seems like neither Connie nor Edward has moved them.
Near the end of movie, when Connie and Edward are talking in the car at a red light, Connie turns back to look at Charlie and the red light turns green behind her, and they don't continue to drive. When the camera focuses on the stop light again while they're kissing, it is back to red and changes to green.
As Constance is driving to the city in the rain, the license plate number on the front of the SUV is different than the number on the rear plate. Later in the film, though, the front plate number has changed to match the rear.
When Connie is in Paul's bathroom to clean and bandage her knee, there are no items in the bottom shelf when she opens the medicine cabinet. But the next shot of her looking in the medicine cabinet shows several items on the bottom shelf.
Connie is in front of the fireplace burning pictures. She has one burning picture in each hand when Edward walks in. In the next shot of Connie (a close-up), she raises her empty right hand to her face. As we pull back, the pictures and envelope are no longer in front of her.
At the beginning of the movie, when Constance is sitting on the steps in front of Paul's building, Paul grabs his books to go to his apartment (telling her he will give her a band-aid). At this moment, the order of the books he is holding isn't the same when he is on the streets and when he's in front of the door (he just went up 3 steps).
Edward's detective friend tells Edward that Paul lives at "433 Mercer Street, apartment 3." However, in the scene in which Paul and Connie meet, the address of the building directly across from Paul's apartment clearly reads, "69 Mercer Street," so Paul's building cannot be 433 Mercer (this address does not exist). In fact, the address of the exterior location for Paul's apartment is 70 Mercer Street.
Paul reads Connie one of the Braille lines in 'Joy Of Cooking' as "My mother makes me chicken. Her chicken makes me cough. I wish that when she made it, she took the feathers off." There is no such line in the actual cookbook.
when Connie oversleeps at Paul's and goes to pick up Charlie waiting at school, you can see flowers on the lawn outside where Charlie waits. the flowers are daffodils and jonquils which would not be growing in the Fall or close to the Thanksgiving holiday. [guess they shot it in the Spring]
The goof items below may give away important plot points.
Ed (Richard Gere) smashes Paul (Olivier Martinez) over the head with the apparently heavy crystal snow globe, causing the fatal injury. In reality, snow globes are made of very thin blown glass and are extremely fragile. Such a blow would have shattered the curio, and at most would have left a few shallow cuts from the broken glass.