Continuity: There's a scene in one of the camp cabins where the two girls are talking. It cuts away from one girl, and she has an ice cream cone in her hand, then cuts back and it's gone. This keeps happening.

Continuity: When the twins are in the cabin and Sharon offers Susan a Fig Newton, the cookies are is a jumble in the box. A moment later, the cookies are in a clean row.

Continuity: When the girls in Sharon's cabin have been booby-trapped, they all wake up screaming to the sound of the bugle. There are shots of them in their beds and then one shot of a girl in the middle of the cabin getting a bucket of water dumped on her head. Considering that the cabin is covered in strings and stuff how could she have gotten there in just seconds?

Continuity: The dad drives "Susan" home from the airport. After he touches her face, he puts his hand down next to him, but when it cuts, his hand is on the steering wheel.

Revealing: When in Boston, while walking through the park, Susan and her mother are obviously walking on a treadmill because the park background is moving way to fast for their walking speed.

Continuity: In Sharon and Susan's isolation cabin, the positions of Susan's celebrity photos on the wall change between shots, after being windblown.

Continuity: When the girls are talking in the cabin after they find out they are sisters, Sharon is holding a cup of ice cream. When the shot alternates from rear to front views, the spoon is in her hand, then in the cup, then back in her hand again.

Audio problem: When Susan is playing the guitar, it has an electric guitar sound. Susan is not playing an electric guitar and neither is Hecky so the guitar should not sound like that.

Other: When the girls leave camp they wave good-bye to each other. If you look closely it is obvious that one of the girls (the one in the distance waving) is a double who does not look like Susan/ Sharon at all.

Continuity: Watch the yellow float that falls into the lake with Mitch, when Mitch is straining to see Maggie. First you can barely see it floating towards the right of the lake. Next angle, and it's behind him to the left.

Continuity: In the cabin when they are coming up with the idea to swap places, Susan has on white sneakers in the beginning of the scene when she is on the bed, and Sharon has on the black Mary Janes. Later in the scene, with no time to change shoes, Susan is seen walking around the cabin wearing the black Mary Janes.

Revealing: When the two girls are singing their song, the girl on the left waves her arm up and it disappears for a second, because of the split screen.

Continuity: When Mitch drives home from the airport, with 'Susan', the car's rear view mirror is gone in the close-ups, but reappears in wideshots of the car.

Revealing: When the "twins" are singing "Let's Get Together" they are standing side by side. Watch closely - because of the split screen, one twin's arm disappears for just a second when she swings it upwards. It actually happens twice - middle of song and end.