Continuity mistake: Bart's bedroom is on the opposite side of the stairs, with his window facing out to the backyard, but after his prayer his bedroom window is facing The Front of the house. Additionally, the style of his window changes as well, going from two horizontal sliding panes with no muntins, to a vertical sliding window with two muntins when Marge pulls the curtain back, then to a having only one muntin when Bart opens his window.
Continuity mistake: When Bart is called up to give his oral book report keep your eye on Bart's book, Treasure Island, and the direction of its binding. The book's binding should be to the left of The Front cover, which has the picture of a pirate wearing a black hat, but the binding changes to the right side (note the cover picture/title) of the cover at times, and when he mentions the publisher the book also changes how it's held by Bart. (00:02:10)
Grandpa vs. Sexual Inadequacy - S6-E10
Continuity mistake: On the book on conspiracy theories that Bart buys, there's a picture on the back of the author. The picture changes several times throughout the episode.
Grandpa vs. Sexual Inadequacy - S6-E10
Continuity mistake: When Homer and Grandpa are trying to sell the tonic at the mall, when Homer is trying to sell tonic to the Critical Man, all the tonic bottles on the table are actually empty. In the next shot, they're full.
Grandpa vs. Sexual Inadequacy - S6-E10
Continuity mistake: When Lisa jumps off the tyre swing, her dress is fairly dirty. When Homer drives off, the bottom is dirtier than before.
Grandpa vs. Sexual Inadequacy - S6-E10
Continuity mistake: At the old Simpson home, Grandpa and Homer run into each other and collide on the porch. In this shot, the windows are dark, but in the next, all the windows are instantly lit up by the fire, which would not be possible in the given time.
Continuity mistake: When the snake from the cashier bites Moe, the bites on his arm never change and only remain in the one spot even though the snake bit several different spots on his arm.
Continuity mistake: In the scene in the airport bar, two pilots sitting next to each other have brown and gray hair, respectively. When they stand up, the hair has switched colours.
Continuity mistake: On the plane, where Marge is starting to act up due to her Fear of Flying, Homer and Marge's seat-belts have mysteriously disappeared.
Continuity mistake: When we first see Homer at Moe's at the beginning of the episode, he is sitting at the bar and there is an ashtray by his glass of beer. But after a quick cut to Moe, we return to Homer and the ashtray has disappeared.
Simpsoncalifragilisticexpiala(Annoyed Grunt)cious - S8-E13
Continuity mistake: When Bart is lying on his bed whipping cupcakes at the wall, there are already 2 on the wall but after he whips the 3rd, there are still only 2 cupcakes on the wall.
Grandpa vs. Sexual Inadequacy - S6-E10
Continuity mistake: When the janitor shows Marge and Homer into the Utility Room, the only equipment in there is a couple of mops. Later, the janitor comes back and pulls out a big vacuum cleaner that we never saw previously.
Grandpa vs. Sexual Inadequacy - S6-E10
Continuity mistake: At the retirement home, Grandpa pulls out some medicine from his cupboard. In the next shot, another medicine bottle that wasn't in the previous shots appears.
Continuity mistake: In the full view of Mr Burns' office when he is talking to Homer towards the end of the episode, there is only one fountain pen holder on the desk, but when Mr Burns tells Homer to leave after giving him his old job back, there are now two holders on the desk.
Continuity mistake: When Mr Burns tells Homer that he is only eighty-one in the meeting in his office towards the end of the episode, there is a fountain pen holder next to his arm on the desk, but when the camera is behind Mr Burns' chair in the next shot, the fountain pen holder has gone.
Continuity mistake: When Homer sobs after Bart dropped his bottle of Dimoxinil on the carpet in the bedroom, he drops the empty bottle next to the remains of the contents. When Homer is looking at Marge in the next shot, the bottle has disappeared.
Continuity mistake: After they say their goodbyes at the power plant, Karl asks Homer if he brought an umbrella and you can see that Homer is standing behind the doorway, but in the next shot he is now standing in the doorway.
Continuity mistake: When Homer opens the doors to the Executive Washroom, there is a sign on both doors, "Executive" on the left door and "Washroom" on the right door. When we see Homer walking with Karl and Smithers, the "Washroom" sign on the right door has gone.
Continuity mistake: When Homer runs out of the house with his new head of hair, there is only one doormat by The Front door. But in an overhead shot of Homer lying on The Front lawn surrounded by the children, a green doormat is now under the door.
Continuity mistake: When Homer parks his car outside Jake's Unisex Hair Palace, the doormat by The Front door entrance is light green but changes to dark green in the next shot.
