Other mistake: In the beginning, the girls arrive at the airport in Chicago and you can see a billboard in the background. Then the credits roll and they land in the sunny Bahamas and as they are driving away in the limo, the same billboard can be seen in the background. Guess they were on a tight budget and had to computer generate the snow over a scene filmed in the Bahamas.
Continuity mistake: In the scene at the party, when Brianna comes up to Alex and Landon, Ashley's hair is perfectly straight, covering her ears. Between shots, her hair keeps switching between tucked behind her ears, messier, and then perfectly straight again a couple time all within a few seconds.