When the teachers rush to see Davy Jones, you can see Marcia and Charlie Anderson out on the floor getting ready to dance. This is a problem because Marcia was on stage just before the teachers scene and Marcia is seen exiting the stage on the far right about 10 seconds after the teachers scene. Also, the next scene with Marcia involves Charlie asking her to dance when we have already seen them on the dance floor.
When Marcia and Doug Simpson are on the hill in the car and he tries to make out with her and she tells him she is not that type of girl, her nose is back to normal, although it was clearly squashed before that scene and all the scenes following.
The position of the Greg's guitar strap keeps alternating between being under and over his collar when he's playing for Cindy. The same thing happens moments later when he's playing while watching himself in the mirror.
Mike drags Carol's needlepoint to his side of the bed (the right side), but when Cindy interrupts what Mike and Carol are doing, the needlepoint is on the left side of the bed where Carol originally was.
When Cindy Brady delivers the Dittmeyer's mail, Larry Dittmeyer is running on his treadmill. The Bloody Mary, in the drink holder, has no celery stick in the glass but, in a following close-up, a celery stick appears in the drink from nowhere.
In the car, Marcia inserts the 8-track of Davy Jones' solo album on Bell in the tape player and the song "Girl" starts playing. That song, however, does not appear on the album.
Mr. Dittmeyer is looking through the driver's side rear view mirror while talking on the car phone. The mirror shows that "objects are closer than they appear" just before Jan knocks off the mirror riding her bicycle. This warning is only on the passenger mirror.
After Jan Brady runs away from home, she is wearing a large black Afro wig and gets a ride from a truck driver. The Brady family drive around searching for her and at 1:08:34 Carol Brady uses her CB radio to broadcast a message that describes Jan as being blonde, which the truck driver hears and realizes that her passenger is actually Jan. It was impossible for the truck driver to know it was Jan because she wearing a black Afro wig. But her blond hair was showing under the wig.
While walking on his treadmill, Mr Ditmeyer's tomato juice glass is being jarred quite a bit, yet does not fall. After getting off the treadmill to get the Brady's mail, the mere movement of the still-running treadmill belt is enough to make the glass slide off, spilling the juice on the belt indicating the glass was anchored to the console initially.
When Jan Brady returns home after she runs away, she runs through the living room where cardboard boxes filled with the family's belongings are stacked. At 1:10:24. Jan accidentally knocks over some boxes and it is apparent that some of the boxes are actually empty. Sound effects of broken items were used to make it appear that the boxes were full of things.
While talking on the CB with Carol, Shultzey announces she just dropped Jan off at a house on Clinton Way. Earlier in the film, it is mentioned The Bradys live on Clinton Avenue.
The handwritten reward sign for the stolen school supplies says "for moore information".