I was watching The Exorcist: The Version You've Never Seen Before (I now prefer to call it the Director's Cut) and I began to notice some continuity errors That is, scenes where the position of something is not the same in one shot to the next. I don't know if these are also in the original version of the film. I'll have to rewatch it at a later time to be sure. But here's what I found (along with another nit or two):

In the scene at the MacNeil party where Burke Dennings is taunting Karl, the butler/handyman, we see Burke leaning on a counter. In the long shots showing Burke and Karl, Dennings is leaning on his left arm. However, in the close-ups, he's clearly supporting his weight on his right arm.

When Damien Karras is in his room talking about his mother's death to Father Dyer, in the close-up shot of Karras' face, Damien does not have his hand anywhere near his face. In the following shot, Karras has his hand to his face.

During the funeral service for his mother, we see in a close-up of Father Karras that his arms are outstretched. However, in the very next shot, a long shot, we see he stands with his fingers touching.

After Regan has been examined by the neurosurgeon, Doctor Klein is talking to Chris MacNeil in the hallway. From a shot behind Mrs. MacNeil, there is no sign that her hand is on her face. In the next shot facing MacNeil, the hand is to the face.

As Drs. Klein and Tanney leave Regan's room, Tanney's arms are at his side. In the very next shot, they're folded across his chest.

Lt. Kinderman and Father Karras are talking about the murder of Burk Dennings. They are walking around the track Karras has been jogging on. At one point, Damien's hands are at his side. In the next shot, they're holding the ends of the towel around his neck.

When Kinderman goes to the MacNeil residence to ask about the murder, he says it happened last week. Did he wait a week before going to the MacNeil home? I suppose Kinderman could have gone to the house on a Monday or Tuesday and the murder took place on a Thursday or Friday. But still, isn't that an awful lot of time to wait before investigating the probable scene of the crime? If the MacNeil household was involved, they'd have plenty of time to destroy evidence.

Why wasn't Karl questioned? Surely, the guests at the MacNeil party would have told Kinderman about Karl's threats to kill Dennings. (I mean, why wasn't Karl interrogated other than it would have distracted from the central plot of the film.)

Kinderman and Chris MacNeil are sitting at her dining room table discussing the murder. At one point, MacNeil has her hand to her face. In the next shot it's gone.

Kinderman asked Chris for her autograph. She asks for a pencil to sign it. Did people really sign autographs in pencil back then? I'd've thought that they always used pens as ink is more permanent?

After the possessed Regan breaks the bonds tying her to the bed, Damien reties her. He binds her hands together, rather than to the bedpost again. Soon afterwards, Fathers Karras and Merrin take a break. When they return, Regan's hands are once again tied to the bedposts. Morever, whereas before the break she only had one blanket on her, upon the priests' return, she has more blankets on top of her. (Did someone go in after the priests left and fix things up?)

Father Merrin, after the break, goes into Regan's room by himself. Damien sits at the bottom of the stairs. Chris enters the room to ask, "Is it over?" The position of her hands change between shots.

"Your mother darns socks in Hell." (TV edited quote)

The old-age makeup on Max Von Sydow here was so good, I actually thought he was old, and not the 42 he actually was when he made this movie.

A new DVD reissue and a Blu-Ray release will be out 10/5/10. The DVD has the 2000 extended cut (aka "The Version You've Never Seen", as noted in the above post), while the Blu-Ray has both the original 1973 cut as well as the 2000 extended cut. More here.