Deliberate mistake: When spoofing Charlie's Angels, the chain that Cindy grabs a hold of as she jumps over the gate wasn't there when Hanson jumped through the gate. It seemed to just appear. This also happens with the baseball bat Hanson uses. It isn't there, until he needs to use it to hit Cindy.
Continuity mistake: One of the deleted scenes on the DVD shows the students suggesting ideas while the news reporters on TV discourage these ideas by reporting on strikes and recalls. The recall mentioned all Japanese cars exploding in rain. Cindy's car explodes, but hers is a Volkswagen, which is German.
Continuity mistake: When the guy in the wheelchair falls out the window, in the next scene he's back in the house. Weren't they all locked in the house? How did he get back in and not let anyone out in the process?
Continuity mistake: For the entire movie, the main female character has a French manicure with long nails. But when they are spoofing "What Lies Beneath" and she lays her professor down on the table, she has short natural nails.
Continuity mistake: During the scene where the clown attacks Brandon under the bed, the pink pillow that's by the headboard when he was doing push-ups is now down in front of the other pillows when he gets dragged under the bed.
Continuity mistake: After Dwight rolls down the stairs Theo says "Look I know you're proud, OK, but just lemme help" then Dwight says "Step it back Candypants" to her, and he points at her, holding his gun in his hand. Then when the shot changes, the gun is now laying on the stairs, and Dwight's hand is empty.
Deliberate mistake: When Shorty is showing Cindy some moves and they are doing the "Right, left, right, left" move, you can see three people walking right behind them. Then, suddenly, the people are gone without the scene being cut. The director has simply just overlapped the scenes while they are doing the moves.
Continuity mistake: When Tori Spelling discovers the ghost's secret room, she walks into it wearing her goggles over her eyes. She hears a noise behind her and turns around, and her goggles are up.
Continuity mistake: When Cindy has to revive Buddy in the freezer, he "lets go" all over the window behind her. Moments later the glass is perfectly clear again.
Continuity mistake: When they are sitting down for dinner, the housekeeper pinches Ray's cheek and leaves mashed potatoes on his face. As the scene goes on, you can see the potatoes on his face one minute and the next his face is clean.