Goofs

When Harris is installing the alarm system, the drill for the insert shots is orange, while the drill shown in other shots is blue.

When Clare picks up the statue to protect herself in the house, she's holding it right-side-up in one shot, then upside-down, then right-side-up, then upside-down again.

Right before Kira's throat is slashed, her nipples are noticeably erect. After the brief cut to Dominic Purcell, they are no longer erect in the next shot (during the actual slashing).

When Kira is thrown by the demon into a wall mirror, she is shown hitting it twice.

When Emma is floating down the stairwell toward the end of the film, a cable or other mechanism is clearly keeping her afloat.

When the ax comes crashing through the window of the gated paranormal house, the iron bars covering the windows have disappeared.

When the main characters are tugging at the metal bars of the fence that has wrapped itself around the house, the bars bend too much to be made of regular metal - they look more like rubber, showing how it is merely a film prop rather than an actual fence.

At the end of the movie, the main characters escape the building inside which they have been trapped at what is supposed to be early dawn according to the storyline. However, the angle of the sun and shadows show that this scene was filmed closer to midday.

In the scene where Kira is trapped in the sinking coffin, the cable to upright the coffin is clearly visible.

When Frances gets killed, you can see the camera operator and camera shadow on the wall.

After being attacked in the hospital, Kira is visited by her two friends. When they go into her room, she is sitting on her hospital bed smoking a cigarette. There's no smoking in any U.S. hospital.