Continuity mistake: In "The Thing and I", when Bart, Lisa and Maggie are in the attic, Bart picks up a book and on the front cover it shows a picture of Homer with the words "Homer, I Hardly Knew Me" by Homer Simpson. But when we see Bart with the book in the next shot, the front cover is now completely clear.
Continuity mistake: In "The Thing and I", when Lisa and Bart watch their father go to the fridge, you can see the spoons in their bowls are pointing to the left, but after a quick cut to Homer getting the fish out of the fridge, we cut back to Bart and Lisa and the spoons are now pointing to the right.
Continuity mistake: In "Attack of the 50 Foot Eyesores", when Homer answers the door and finds the Lard Lad statue in front of him you can see there is a door knocker on the door and a green doormat on the step. But when he answers the door a second time, the door knocker and doormat have gone.
Continuity mistake: In "Attack of the 50 Foot Eyesores", the executive goes to the piano and you can see a penholder on his desk. But the camera angle changes to behind the piano in the next shot, the penholder has moved position and there are now more items on the desk.