Continuity mistake: When Libby tells the story of how she met Henry, you see her falling down a hill. Her guitar is rolling really hard. However, in the next shot it's just gliding gently down the hill.
Continuity mistake: When Daphne first goes out with Ian, they are seen near a river and when the camera angle is from the front her hair is seen blowing in the wind, but when the camera angle is from the rear her hair is not moving. Happens about 3 times during the scene.
Audio problem: When Colin Firth's mother shoots down the tree where the bird is resting, and the branch falls, you never hear the sound of the branch hitting the ground.
Plot hole: When Henry announces that he is dropping his candidacy, he steps off the podium and the press start taking his picture. Yet when he walks out none of the journalists want to ask him questions, even when he punches his adviser of 17 years.
Continuity mistake: In the scene where Daphne is serving the meals at the first wedding, she goes to Noel's table and Noel's hands are together. In the next shot, one of Noel's hands is holding her neck up and the other one is resting on the table.
Continuity mistake: In the scene after the fashion show where Daphne confronts Clarissa, they are in front of the food table. Daphne grabs a piece of food but never picks it up, she stands there with her hand awkwardly on a piece of food while she's talking.
Audio problem: After Daphne has walked down the runway after the unintentional entering, when she poses at the end of her walk, she falls off the runway and into the arms of a British man. He supposedly says something like, "Are you all right?", but the way his lips move don't make it look like that is what he has said.
Continuity mistake: In the scene where Daphne and Henry are eating toast, she is holding the bread with both hands when the camera is focused on her and only one hand when the camera is focused on Henry - it switches back and forth several times.