During the water park scene, the body builder is seen to remove his sun glasses and toss them on the lounge chair. In the next shot, they are back on his face. In the following shot, they are back on the lounge chair where they landed when he tossed them down.
When Robbie kicks Marcus in the groin after chasing him to the top of the boathouse, Robbie has a shoe on his right foot when he kicks Marcus. In the next shot, when Robbie grabs his left foot in pain, he is bare-footed. In the next shot where Robbie is on the ground still holding his left foot in pain, the shoe reappears on his right foot.
The wives are shown sewing "uniforms" for the big basketball game. During the game, the men wear t-shirts with the logo of the water park, and a logo of the t-shirt company clearly visible on them - obviously not made for them by their wives. The women arrive in newspaper cheerleader costumes - also not what they were sewing.
In the basketball game at the end of the movie, the wife, baby and daughter of the guy on the opposing team who steals the dessert from his daughter are shown sitting with the daughter in the left chair (right on the screen) and the wife and baby in the other chair. When the father steals the dessert from the daughter, they are in opposite chairs.
When you first see Donna in the pool, she's standing up in the middle of an inner tube with the American Flag design in the water. In the next scene, she's on the other side of the pool sitting on the tube with the design facing upwards.
During the conversation in which Lenny is holding the KFC bucket, the red side of the bucket is facing the camera, then after a cut-away, the white side is facing the camera, then after another cut-away, the bucket is gone.
When everybody's entering the lake house for the first time, after Rob says "Welcome back to 1978," and the camera shows all of the characters, a crew member can be seen running past one of the windows on the left.