Continuity mistake: When Father Harris' lips are stuck to the crucifix he is trying to pull it loose with his right hand. When it cuts he is pulling it with his left hand. (00:04:55)
Continuity mistake: When Cindy first meets Hanson, the big knife Hanson holds changes angles in his hand between shots. (00:15:50)
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. (00:14:10 - 00:37:30)
Continuity mistake: Cindy is driving to Kane Manor, and she's singing along to a song. Then the song tells Cindy to shut up. After this Cindy goes from holding the sides of her steering wheel, then the top of the wheel, then back to holding the sides between shots. (00:14:00)
Continuity mistake: When Cindy is driving along, singing along to a song in her car, in wide shots of the car, you can see the road she drives down has a white fence running along both sides of the road. But in shots of Cindy in her car, a white fence should be visible, but isn't there. (00:13:35)
Continuity mistake: When Shorty's plant is growing we can see its leaves going over the edge of the pot its in. When it cuts to the pot cracking no leaves are in sight. (00:39:10)
Continuity mistake: When Cindy sits on top of Oldman there is no shadow across her face. When it cuts to her saying "I think she's starting to suspect something" a large shadow has appeared. (00:37:55)
Continuity mistake: When Buddy uncovers the painting of Kane's wife, the spider web pattern changes between the shots as he removes it. (00:29:15)
Continuity mistake: When Hanson takes Cindy's toothbrush, he puts it into the left side of his mouth. When it cuts, it has suddenly moved to the right side of his mouth. (00:17:10)
Continuity mistake: After Cindy has built her big yellow truck, she ploughs through the door. In one shot we see a large part of the bottom of the wall to the left of the door get knocked out too. In the next shot that part of the wall is totally intact. (01:01:55)
Continuity mistake: As Dwight falls from the side of the building, his jacket changes from closed to open to closed to open as he falls. (01:01:05)
Continuity mistake: During the duel with Kane, Dwight shoots the leg of a table so that the table falls. He then rides off of the table like a ramp. When he lands we see the table sitting right in the middle of the hall. Later, the table is now right by the wall. (00:59:35)
Continuity mistake: When Hanson picks up the turkey and puts it on his hand, there is nothing under the wing of it. Then a rosemary sprig appears under the wing. It then falls out in a wideshot, yet it's back in the following closeup and then finally disappears in the next shot. (00:23:35)
Continuity mistake: When Buddy and Cindy are going to check out the music room and Buddy is telling her the story about high school, they are walking down a hallway, but when the view changes to the room with the bloody footprints they walk in from the lobby. (00:28:18)
Continuity mistake: When the butler (Chris Elliot) goes to bring the potatoes from the cart to the table, you can see on the left side of his face he has a small piece of potatoes there. When he goes to eat the potatoes from his hand it's gone. (00:22:45)
Continuity mistake: When they are passing the picture of Kane's wife around the table Brenda is sitting right next to Ray. After Ray is done with the picture he is about to give it to Brenda. When it cuts Shorty suddenly has the picture. (00:41:15)
Continuity mistake: When Buddy informs everyone about the poltergeist, Brenda picks up the cleaver from the table twice between shots. (00:42:45)
Continuity mistake: When Buddy chucks his rugby ball at Cindy, it hits her in the head, and she crashes into a table, smashing the table and vases up. In the next shot of her, the table and vases are much more smashed, and everything is in a much different position. (00:27:20)
Continuity mistake: When Tori Spelling is going up the wall having sex with the ghost, as she goes up you can see her hands down by the red headboard clutching it, but in the next shot they are raised above her head, then in the next shot they are down by the headboard again. (00:30:55)
Continuity mistake: When the main star gets locked in the freezer we see the temperature gauge go down to cold, but when we get an external shot of the door the gauge is at the top again. (00:55:30)
Answer: I want to know this so badly as well and can't find it. The Graduation Song is not right.