Continuity mistake: When Bart leaves the school, you can see that his skateboard is green and perfectly flat. But when he is skating through the crowd and past the people at the bus stop, the skateboard has an orange stripe down the middle and is raised at the rear.
Continuity mistake: When Homer ignores Lily, she gets upset then runs out of Moe's, and in the interior shot the door is hinged at the left, but in the next exterior shot that door is hinged on the opposite side, while Lily is crying outside. (00:09:35)
Continuity mistake: When Marge walks out of her aunt's house onto the porch, the screen door's handle is at the right side, but in the following shots the screen door opens the opposite way. (00:10:05)
Continuity mistake: While Lily continues to "light up all the men's lives, except Homer's," when she walks into the power plant with picnic lunches, Homer is wearing a solid peach colored tie, but in the next shot it's a striped peach and pink tie. (00:11:00)
Continuity mistake: When Homer takes Lily home after her date with Burns, as Homer pulls up to her house, the doorknob is on the left side of its front door, but when Lily enters the house, the doorknob is on the opposite side of the door. (00:16:20)
Continuity mistake: At the end, when Lily is back at a pub in England and meets Homer's doppelganger, his single shirt pocket and button are at his right side, but as he and Lily leave the pub arm in arm his shirt pocket and button are on the opposite side. (00:20:20)
Homer Alone - S3-E15
Continuity mistake: When Homer is singing to Maggie, he is standing by the bed. But in the next shot, Homer disappears and reappears.
Continuity mistake: Seymour's time as a POW in Vietnam changes throughout the show. One episode he mentions having been one for a year and a half. Another one he says it was two years. A third one he says it was three years.
Continuity mistake: This is a mistake for the introduction from seasons 2-20 (1991-2009). When Homer screams, he turns round. You see this in a wide shot. There are no boxes to the right of the door in the garage. However, two just appear out of thin air when he runs through the garage. (00:01:50)
The Simpsons Christmas Special: Simpsons Roasting on an Open Fire - S1-E1
Continuity mistake: Lewis changes from black to yellow when Milhouse dares Bart to pull Santa's beard off. (00:14:10)
Continuity mistake: When Homer's Vegas wife shows him the video in front of Marge, it shows Homer kissing Ned. This didn't happen when she showed it in the Vegas episode.
The Simpsons Christmas Special: Simpsons Roasting on an Open Fire - S1-E1
Revealing mistake: After Homer brings Santa's Little Helper home, Homer and Marge hug, and if you look behind them, the background is upside down. There is a picture hanging upside down, and there is a lamp which seems to be hanging from the ceiling. Then in the next shot, the background is normal. (00:21:40)
Audio problem: After the donut delivery guy asks Carl why all the donuts are piling up, Carl responds with Lenny's voice.
Homer's Barbershop Quartet - S5-E1
Continuity mistake: When you see a shot of the church from outside in the scene where the bee sharps sing there, look closely at the sign. It says 'Also: The Bee Sharps', only they don't name themselves that until later on in that episode.
The Simpsons Christmas Special: Simpsons Roasting on an Open Fire - S1-E1
Continuity mistake: While having breakfast, all of the Simpsons' glasses of orange juice keep disappearing and reappearing throughout the scene. (00:05:35)
Continuity mistake: Ms. Krabapple takes the cellular devices from the children in her class and puts them in a Laramie Cigarette box. She dumps the box into a desk drawer filled with frogs. A few seconds later there is a shot of the class from her point of view with all of their cellular devices on their desks. (00:03:00 - 00:08:15)
The Girl Who Slept Too Little - S17-E2
Continuity mistake: At the end of the episode where Homer is on the field talking to Buck the baseball player, the stadium is crowded. When Homer and Marge are leaving in their baseball golf car one second later, the stadium is empty. (00:20:40)
The Bonfire Of The Manatees - S17-E1
Continuity mistake: When Marge is in the car upset at Homer, the door to their house changes from open to closed then open again between shots.
Continuity mistake: When Maggie goes through the checkout at the beginning, Marge's trolley is grey and has a red handle. But in the next shot, when Maggie pops out of the bag, the trolley handle is turquoise. (00:00:30)
Continuity mistake: In the introduction, initially Maggie's seat is light purple. However, in the wider shot of her and Marge, the seat changes to a burgundy colour. (00:00:50)
