When Norman the dog jumps up at Kelly and she falls back against the mirror, causing it to topple over backwards and break, the glass shatters into tiny fragments. But towards the end of the movie, when Lynn and Kelly are sweeping up the remains of the mirror and tipping them into a bucket, the pieces of glass are much larger.
During the pumpkin-truck ride, Mr. N causes the driver to panic and go out of control, causing the pumpkins to fall out of the truck. In the next shot, a man rides a bike fast and trips on one of the pumpkins, crashing to the ground. But when the truck comes to a complete halt in the next shot, the bike rider stands with a pumpkin stuck around his head, struggling to get it off.
While sitting listening to Lynn and Kelly describing the moonstone and their plan to get it, Mr. N picks his hat up with his right hand. In the next shot, getting up and walking, he has the hat in his left hand.
During the flat-tire scene, Aunt Agatha uses Kelly's wand to make the tire round again, but when it doesn't work, she tosses the wand at George's feet and Kelly goes to retrieve it. During the wide shot, she's reaching to her far right rather than where George is standing. But when the camera cuts to a close-up of Kelly, she's reaching where the wand landed with no problem.
When Oscar goes up with the balloons, a line is very visibly attached to him and can be seen several times.
When the family is in the living room, the reflection in the television appears to show some sort of light (the kind with an umbrella reflector around it)