Continuity mistake: Right before Jacob comes through Bella's window, it shows her sleeping and "dreaming" of Victoria coming to get her. If you look, the camera really focuses on the dreamcatcher and how it's hanging above her on the bedpost. It is hanging off to the side of the middle hump. Immediately, Jacob comes through her window and focuses in on the dreamcatcher hanging on the bedpost which is now neatly hanging in a completely different way, perfectly laid over the center of the bedpost.
Continuity mistake: When Bella is at the cafeteria table with Mike, and he is asking her to a movie, her hair keeps moving from behind her ear to hanging in front, and back again.
Continuity mistake: In the scene where Bella is in the meadow talking to Laurent, Bella's hair is at first straight and then in the next scene it is wispy and pushed back and then it is straight again.
Continuity mistake: In the scene where Jacob is talking to Bella on the beach about Victoria, his shirt starts off as a dark gray colour, then it changes to a brown colour. It does this a few times during the scene.