When Desiree first enters the parking garage looking for Peter, she is wearing black high-heel boots. Later in the scene when she is being chased, she is wearing black knee-high socks and black running shoes.
At the party, when Barbie swigs her glass of champagne, there is only a tiny bit left. In the next shot, the glass is half full.
When the movie opens on April 1, 2007, Peter Welling is a candidate for the U.S. Senate and discusses the state of his campaign. As of that date the next primary election would still be 17 months away - too far away for a person to be running a Senate campaign.