Continuity mistake: When David and Elizabeth are trying to find the street address 425, it shows the numerals 425 on a porch with steps starting up from the left side, making a 90 degree turn to the left and continuing up more stairs. There is nothing on front face of porch but the numerals, boarding and stair railing. After Elizabeth says, "Not really" the camera cuts back to the porch and stairs but now there is a light fixture and a window or door on the front face. Then we see David going up stairs from the right side. But when we see them leaving, it appears that they come down stairs that look like the ones from the first scene.
Continuity mistake: At the beginning of the film when David first sees Elizabeth in his apartment, they both start screaming. The camera shows her screaming but then the angle changes to show the side of Elizabeth and she stops screaming, when it goes back to the front of her she is still screaming.
Continuity mistake: When Abby is standing at the foot of Elizabeth's hospital bed next to the "ghost Elizabeth", she crosses her arms across her body right under her breasts. The very next shot, as we hear Dr. Rushton speaking as he's coming into the room, Abby arms are down in front of her with her hands clasped. (00:48:20)
Continuity mistake: When David and Elizabeth are in the restaurant next to the collapsed man on the floor, David says that he's going to need a sharp paring knife and a bottle of vodka. We never see anyone approach David or place the knife and vodka next to David on the floor but it just is there when he reaches for it.
Revealing mistake: When Abbey grabs the knife and threatens David, David falls and hits the tea party table, sending the tea set onto the floor. As Elizabeth crosses to be next to David, her foot hits a pink tea cup piece on the floor sending it rolling away behind her. As a ghost her foot should have just passed through the object. (01:06:45)