Continuity mistake: When Marge runs back to the kitchen to retrieve the wedding video, the house is ablaze. In the next shot, when the mob is carrying the car away, there are no flames visible in the house.
Continuity mistake: In front of Krusty Burger, when Lou carries a naked Bart to the sign post, the post is embedded directly in the concrete walkway slab, just beside the left corner of the patch of grass. Once Bart is cuffed, the sign post has actually moved down about 4 feet, and is also now embedded directly in the grass at the right corner. In following shots, it's at the left corner of the grass and then right again.
Continuity mistake: In the cinema, when Homer tells everyone how boring this is, behind Bart, Lisa, Maggie and Marge sits Otto, Kirk van Houten and Barny, but in the next shot behind them sit Otto, Jasper, Kirk van Houten and Moleman.
Continuity mistake: When President Schwarzenegger tells Russ Cargill he will have to go back to making family movies, there is a "Diaper Genie" promo poster on the Oval Office wall and on the immediate left of President Schwarzenegger's desk. But the promo poster disappears and the walls of the Oval Office become further from the desk in the next long shots.
Continuity mistake: When Homer and Bart are fixing the roof (near the beginning) there is no tree near Ned Flander's house. Later on Bart is on a tree next to Ned's house talking to Ned Flanders.
Continuity mistake: When Maggie does her disappearing act through the sinkhole, and Marge rushes to get Homer, the wooden porch swing is directly in front of the window, with its top beam as high as the top of the window. When Homer says, "This dome can play tricks on you," note the door and window behind Marge, because the swing is now gone.
Continuity mistake: When a naked Bart is cuffed to the sign post, beyond the grass behind him is concrete walkway then the curb. Then when Homer steps out of the car, the grass goes right up to the curb's edge, but when Bart asks about pants, the walkway is back again between the grass and curb.
Continuity mistake: When Marge looks at the magnetic words "a thousand eyes" on the fridge and asks Grampa about it, other than the highchair Maggie's sitting in, there are two chairs around the kitchen table - one Grampa's sitting on and one empty chair, but in the next shot as Homer introduces the newest Simpson there are now three chairs - Grampa's chair and two empties, the one beside Marge appeared out of nowhere.
Continuity mistake: When Chief Wiggum orders his men to open fire on the dome, and the bullets ricochet back, the officer standing farthest from Wiggum is wearing blue gloves on both hands in the overhead side shot, and the other officers are not wearing gloves. However, in the shot facing them, the officer kneeling farthest from Wiggum is the one wearing blue gloves, and now all the others are barehanded.
Continuity mistake: When the angry mob breaks down the front door of the house, the door knob is on the right side of the fallen door, at Chief Wiggum's feet. However, when Maggie breaks her bottle and thrusts it forward, in the next shot as Mr. Teeny turns and runs away, the doorknob is on the left side of the door, at Bumblebee Man's feet.
Continuity mistake: After Homer nailed the bedroom door shut and then mimicked the sound of a chainsaw, when the hands of the angry mob push through the holes again, we see Marge and Lisa sitting at the edge of the bed where the bed's tall footboard should be. The footboard is back when Spider Pig pushes the plank off the windowsill.
Continuity mistake: When Homer is grooming Spider Pig he is in Bart's room and it's on the end of the house because you can see the corner of the house, then he walks out of the room and goes in another room but that room is on the end of the house too, you can tell it's a different room by looking in the background so it doesn't make sense that both rooms are in the same place.