When Carly is on the phone trying to reach Paige and her boyfriend, Bo hits the window once without it breaking, then hits it again so it breaks. Later, when Blake is checking the voicemail, you hear the window break the first time it's hit.
Carly's height changes throughout the film. This is explained
in the extras; because Jared Padalecki is so tall, Elisha Cuthbert wore wooden shoes in the scenes where her feet weren't shown. In some scenes, she is up to Wade's shoulder. In others, she is up to his chest.
When Bo is talking to Carly through the truck window he is carrying a container of things, and at one point he throws all of the things on the ground. You can clearly see all of the items strewn across the ground. In the next wide shot, though, all of the items are missing and are never shown again.
When Carly and Wade are looking around in the House of Wax for the first time, Carly dusts off a section of a mirror. Between shots the mirror goes from having only that small section wiped off to having the whole surface wiped free of dust.
Carly turns around to look out the window when the housemaid wax figure in the kitchen startles her. The figure's back is to the window when Carly accidentally tips it over and smashes it. About a minute, earlier when Carly first stepped into the kitchen, the figure was facing the wall to the left of
When Carly and Wade first decide to go in to the church to look for help, the sun is shining and shadows are forming to the left of the screen as we see the view of the front of the church. From shot to shot as Wade and Carly then walk in to the church, the sun is gone and the light is dull with no sunshine. But when Bo turns around in the church the sun is beaming straight through the window on to him from the front rather than from the right, and when Wade and Carly close the door and walk out the sky is still overcast with no sunshine.
When Carly first sees the reflection of the man in the mirror, she is standing directly in front of it. When she is explaining to Wade what she saw, she is alternately standing further away from, then closer to the mirror.
After the group takes the detour, and they are driving on the back road, there is a shot of the red car from behind. If you look at the very bottom of the screen, you can see the equipment that the car is hooked up to.
During the scene at the campsite close to the beginning, in the morning shortly before Carly goes to the turlet, the birdsong that can be heard is clearly the song of a European robin that would not be found in America.
When Bo is strapping Carly into the chair, he starts with her right wrist and you can see her trying to push him away with her left hand, but once he straps her right wrist, both of her wrists are suddenly strapped down.
When Carly and Wade first enter the town, they pass a movie theater marquee. The name of the movie that's airing is incorrect and grammatically wrong. The movie is listed as "Whatever Happened To Baby Jane?" The true title is "What Ever Happened To Baby Jane?"
When Wade is coated in wax, his eyes are covered too. But when Dalton finds him his eyes aren't at all affected by the wax and are moving around, and he even retains the ability to cry. After being slashed by Vincent, his skin peels off and his eyes go completely up. Later, when Nick and Carly are fighting with Vincent, Wade's eyes are down.