Revealing mistake: When the Headless Horseman is about to kiss Catrina's stepmother, you can see his actual teeth behind the filed ones. Christopher Walken's teeth are blacked out and their outline is visible against his tongue during the closeup of his face. (01:37:20)
Factual error: In the montage sequence showing Drew Barrymore hanging out with the math club, they have a Pi poster with 3.1457869986. Only the first 3 digits are actually correct. (Pi = 3.1415926535897...) (00:25:20)
Continuity mistake: Look carefully when they transport to the Mexican Restaurant. Her night dress is unbuttoned at the top but mysteriously closes in a matter of seconds.
Continuity mistake: After the 2nd battle (when Joan got an arrow in the chest) she wakes up her soldiers the next morning and uses the tower to break down the English bridge. At the bottom of the bridge when its falling (inside the fort), no one is near the bridge when it's falling except the guy who bad-mouthed Joan earlier that morning. Then in another shot there are at least eight guys getting crushed by the bridge.
Revealing mistake: When Tracey goes around a corner on the boat, he clips through it. (00:06:04)
Continuity mistake: When Bill Lumbergh pulls into his parking space at Initech, the sign reads "Reserved for Bill Lumbergh, Division V.P." When Peter later pulls into the same space the sign only reads "Reserved for Bill Lumbergh." (00:02:50 - 00:41:05)
Continuity mistake: When Craig talks to Maxine in the little pantry on the 7 1/2th floor the way he holds his cup of coffee (both hands around the cup or one hand at the edge of the counter) changes several times. (00:16:10)
Continuity mistake: When Amelia jumps in the water to save the the little girl there is tape on her mouth. A moment later, the tape is not visible.
Continuity mistake: After Jack shoots the dart at the crocodile trapped in the helicopter, it is visible in the animal's jaw. After the attack by the second crocodile, the dart has gone. A moment later it is back again. (01:09:20)
Continuity mistake: Ed's feet change position between shots when he is sitting in the bathroom on the hamper and talking to Cynthia. The hamper also changes position in the overhead shot. (01:14:20)
Other mistake: The death warrant for "Arlen Bitterbuck" is dated 1935 but the subtitle in German says 1985. (00:25:15)
Continuity mistake: When Maggie and Ike are talking outside at the luau, Ike's flower necklace is in a different place every other shot. (01:11:15)
Visible crew/equipment: In the scene where Amanda Peet goes crazy in the restaurant and throws the china around, there is a mirror on the wall of the restaurant, in which you can clearly see the lower half of a man wearing jeans in some shots and then in others he is not there. (00:20:00)
Visible crew/equipment: Before the last battle, when the Wendol warlord nears the Norse village he's on horseback and raises his arm swinging his weapon. It cuts to his closeup, and under his right arm there's a visible plastic slider buckle on the strap (looks like nylon) of his bear costume. (01:21:15 - 01:30:55)