Continuity mistake: Near the end when the vampires are trying to get into the crypt and Jim Carrey has locked them out, we see two vampires trying to enter the room through one door and others going around to get in through the other entrance. When they get in, the vampires have reversed which entrance they were trying to use - the ones who stayed at the first door enter through the second door and vice versa.
Continuity mistake: In the bar scene when Billy is playing the saxophone on stage, his wife enters the bar with her boyfriend. The saxophone music keeps playing after Billy starts glaring at them, even though Billy has stopped blowing air into the horn and is not pushing the horn's buttons.
Revealing mistake: There are several instances where you can see that the bandages used to wrap up the girls are pre-assembled. When the first girl is "waxed" you can see there are no joins between the bandages, they are all in one piece - almost like a body stocking. You can also see this later with Elizabeth, and it becomes more significant because you see the bandages being wrapped around her head as normal, and then when Watson pulls them off, they come away in one piece like a balaclava, which of course shouldn't happen.
Revealing mistake: In the scene where Herbert and Dan re-animate the dead corpse, watch closely when Herbert rams the little buzz saw into the corpse's chest. At the bottom of the screen, you can see where the fake chest ends.
Factual error: There's a couple of scenes where Izzy goes into a speech about how he came to America when he was 10, and he owes so much to that country. The historical Izzy Einstein came to America when he was 15.
Continuity mistake: When Jackie puts the sword in the wall you can see a hole made by the sword from an earlier scene take. When it cuts back to another shot the hole is gone. (01:08:30)
Continuity mistake: When Jennifer finds the small boy, she removes a sheet from a mirror. In the next shot the sheet is draped back over the mirror again and then gone again. (01:35:50)
Revealing mistake: When the guard that wants to kill the fool is hit by an arrow, you can see the outline of a protection plate or something like that under his clothes.
Continuity mistake: When Dutra forcibly grabs Abbey's hand and bends it, her hand is palm up. When the shot changes, her hand is palm down.
Factual error: The KGB agent hunting Jonathan is carrying a Spanish Campo-Giro pistol. There's no way a KGB agent would carry a foreign sidearm in a Soviet Bloc country, especially one that was phased out of service in the late 1920's.
Continuity mistake: When Taran, Princess Elonwy and Fflewddur try to escape from the Horned King's castle, Taran opened the gate by removing the chains. The next shot the gate is closed and chained, the last shot the gate is open again, and the boat is pushed trough by Taran. (01:06:33)
Factual error: In the beginning when the college grads are making drinks in the blender, they're using Citrus Hill orange juice. The movie takes place in 1971 and Citrus Hill wasn't on the market until the mid 80s.
Continuity mistake: In the flashback scene (where Cassie has the crazy long hair) we see "young" Cassie perform a routine in the studio. Zach comes out of the shower towelling his hair and watches her. We see his hair is messed up having just been roughly dried with a towel. The next shot is Cassie dancing, then the next shot is back to Zach, and this time his hair is combed nicely down.
Factual error: The Air America helicopter that flew Tom Hanks and company out to the site was a Bell 212 (Twin Huey) The movie allegedly takes place in 1962. That model Huey was not introduced until 1968.
Revealing mistake: On the ledge Robert Hayes is attached to the wall by a wire protruding from his shirt.
Suggested correction: Not true, the ledge was only 2 feet off the ground.
Factual error: In the shot of Florence with several bridges and the river shown, cars and motorbikes can be seen going across the lowest bridge in the shot. (00:10:10)
Revealing mistake: Just before Michael and Ellie get out of his car, a fire extinguisher is seen mounted above the dash. Michael opens the hood and the engine begins smoking. Michael reaches into the car for the extinguisher. You can see through the windshield that he is handed another extinguisher instead of removing the one from its mounted spot. The mounted extinguisher is still visible in its holder. Likely done to preserve pacing so he doesn't have to fumble with the clamps on the mounted one.
Other mistake: During the epic love scene between Helen Shaver and Patricia Charbonneau, look carefully at a closeup shot as Patricia kisses Helen. Parts of each one's hair is inexplicably wet and they haven't been fooling around long enough to sweat.
Continuity mistake: When Wolfgang first gets trapped in the bubble, he says it's air tight, and he cannot breathe. When Ben goes into the bubble to spy on Lori, he's in there for several minutes and has no trouble breathing.