(at around 51 mins) After Kathy is attacked, the marks on her face disappear in the next shot.
(at around 13 mins) At breakfast Arthur has coffee spilled on him. When he opens the door to greet Benjamin Moss the shirt stain is much larger, but then gets small again as they cut to the inside of the apartment.
(at around 51 mins) When Kathy is attacked by the Jackal, he claws at her right breast and it falls out of the bra (but her nipple covered by a scrap of her shirt). In the next shot, her breast is back in the bra perfectly.
(at around 1h 4 mins) Just before everyone is looking through the book in the library, Rafkin has blood all over his right hand. But a little while later, his hand is completely clean.
(at around 37 mins) When the Angry Princess lies in the tub, Kathy's sleeves are alternately up/down between shots.
(at around 5 mins) At the beginning, Cyrus makes a joke about "quicksilver flares". Except quicksilver is another name for Mecury. It cannot be used in that fashion.
In the DVD version of this film, the ghosts' backstories are given. It's said that The Pilgrimess ghost is still locked in the stocks that she died in. As stocks only held the feet, the person is bound in a sitting position. When The Pilgrimess appears, what she's actually locked in is a called a pillory which holds the neck and hands, not the feet so the person is able to stand.
(at around 1h 2 mins) In the library when Dennis presses his bloody face to the glass, you can spot various other bloody face smears at his head height from previous takes.
(at around 55 mins) As Arthur and Kalina discover that Kathy has disappeared, one of the walls moves when they lean on it.
(at around 1h 1 min) Jackal casts shadows on the walls before he attacks Arthur.
(at around 15 mins) The family is looking at the computer with the lawyer and he plays the movie. The stop button is pressed during the whole movie clip , where as the play button should have been pressed.
(at around 51 mins) When the Jackal attacks Kathy, he has one hand on her throat, which is what is holding her up, but when he lets go she does not fall down.
(at around 46 mins) Bobby falls on the floor in the basement, dropping his recorder. In the background, amongst the many whispers of the ghosts, Jean warns Bobby to get up and leave the basement. Right after that, a voice whispers in the background, and the caption reads "Leave me alone." However, with the volume turned up, the voice (belonging to the Jackal) clearly cackles a sarcastic 'Listen to your mother!'
(at around 1h 5 mins) When Kalina is explaining the Black Zodiac to Maggie, his mouth does not match the words that are being spoken.
(at around 1h 3 mins) After Arthur punches Rafkin and they fall to the floor you can see the reflection of a crew member behind Arthur on the desk.
A crewmember with a clapperboard can be seen very fleetingly during the "bloody bathroom" scene.
When the house starts to transform inside, a pair of hands of the crew can be seen pushing one of the doors when it is supposed to close automatically.
A clapperboard can be seen when Bobby is being lured downstairs.
(at around 57 mins) Dennis said that the walls of the house were soundproof, but when he is trapped in the room with one of the ghosts, Maggie is yelling at him to move and duck. He can clearly hear her, and she can hear him, even though he isn't supposed to be able to.
(at around 13 mins) It is established that Arthur has no money. He has past due bills, he cannot afford a bigger house, and he is a math teacher. How does he afford a live-in nanny?
Dennis states that anyone who touches him, has their whole life flash before his eyes. Yet Maggie clearly touches him on the back several times while in the basement, and nothing happens to him, not even a twitch.
(at around 1h 4 mins) In the Arcanum, they mixed the Angry Princess's and the Bound Woman's pictures.