Continuity mistake: When Jason Lee is driving the car over the humps in the road, Julia Stiles is in the passenger seat. In the shot before they take off Jason Lee is in the driving seat, when they show the shot of the car in mid air Julia Stiles is now in the driving seat, and in the shot as the car lands they are back in the right seats.
Other mistake: In the main titles, for casting, the name "Brennan Dufrense", is listed. It should read 'Brennan Dufresne'.
Audio problem: During the wedding part at the end the movie, when Paul announces he doesn't want to marry Kerry, Kerry looks at him and says, "Paul?" but you can see she is really saying, "What?" The voiceover comes in late as well. This is on the video version.
Continuity mistake: Watch Ray's sandwich when he's got the 'death grip' on the main character: The sandwich magically replenishes itself between shots.
Continuity mistake: When Jason Lee is beat up by Julia Stiles' ex-boyfriend, Ray, he is thrown into a garbage can and Ray kicks the wheel so it starts to roll, the opening is on the right side of the screen. When Selma Blair sees him in the alley falling out, he falls out of the left side of the garbage can.
Continuity mistake: In the first dinner scene, after Jason Lee has set off the car alarm everyone else runs outside to see what is going on. However Julia Stiles now has her coat on which she was not wearing seconds before. Earlier on you can see all the coats lying on the bed upstairs. (00:29:00 - 00:30:00)
Continuity mistake: When Jason Lee is hit in the face with the egg, you can see the egg hit him on the left side of the face. Then when the camera moves to show the back of his head, the egg is on the right side.