Revealing mistake: After the sniper is shot he falls through the wall. Look at his silencer when he hits the ground - it bends where it attaches to the muzzle. A real metal silencer wouldn't do that. (00:41:25)
Revealing mistake: In the end when Mulder is reading the paper in the park. The paper is clearly a prop. Only the frontpage is real - when he puts the paper away you can see that the rest of the paper consists of blank pages. (01:45:45)
Revealing mistake: When Sandra Bullock and Nicole Kidman drag her sister's "dead" husband/fiancé into a room, the door hits him on the head and his eyes move.
Revealing mistake: Near the end (DVD), when Sadako comes out of the TV, you can see where her finger extensions have been placed (you can see the join between her real finger and the fake one). (01:22:50)
Suggested correction: She's not wearing finger extensions. There are small prosthetics to make it look like her fingernails are missing, but her fingers are normal length.
Revealing mistake: In the scene where Murdoch falls off the building, you can see the rope that is holding him up, twice. (00:59:00)
Revealing mistake: When Natalie is in the old building and she is looking around, she opens the door and Parker's dead body falls out onto the floor. When it cuts to a close up of his body, you can clearly see the side of his neck pulsating although he is dead. (01:19:50)
Revealing mistake: After Beloved's ghost throws the dog against the wall its eyeball hangs out. In some shots the dog's real eye is visible too. (00:01:30)
Revealing mistake: As Ted is being burnt by the fire, you can see his body trapped underneath the debris. In a side shot of Ted it is very obviously a stunt dummy as the left arm and head stay completely still and the arm remains completely stiff despite hearing screams and shouts from the pain.
Revealing mistake: As a homage to the original; when Norman carries Marion's dead body, wrapped in the shower curtain to the car, you can see her bra strap through the curtain.
Revealing mistake: In the scene near the beginning it shows a big guy converting a 7-10 split and celebrating. If you watch it closely you will realise that the 7 pin is lined up too far to the left and the ball is already in the gutter when it hits the pin. The movie makers could have at least bothered to repaint the pin placement lane markings so it would not be so obvious that the pin had been moved.