Continuity mistake: In the scene where Christina decides not to be afraid anymore and runs after Peter, she comes out of the house and first shouts while facing in the wrong direction. She knew that he went the other way, because she saw him leave. (Shot at different times, confirmed on DVD commentary.)
Continuity mistake: When Christina, Courtney and Jane are singing a song with everybody in the restaurant, a guy with glasses says a line of the song while bending over, then straightens up toward Courtney. In the next shot, he is still bent over, and again he straightens up toward Courtney.