Continuity mistake: When Apu awakes, he has a closed note pad, and the table looks small. In the next high-angle shot, Apu's book is open and face down, with paper on top of it and a pen beside it. The table is also bigger, with Bart sitting there with his breakfast things too.
New this month Continuity mistake: In "The Thing and I": After the kids have found Hugo in the attic, when Marge and Homer return home, both front door knobs (inside and outside) do not have backplates, but once Hugo escapes both door knobs have backplates. The two backplates vanish and reappear repeatedly in following shots. It's funny because when they leave to search for Hugo, Homer shuts the door with no backplates, but then Bart uses a key in the backplate to lock the front door.
New this month Continuity mistake: At Mo's, when Grizzly Shaun is talking to Smithers about Mr. Burns, Smithers is wearing a grey suit, but when Mr. Burns says "A good old fashioned lemon party", Smithers is wearing his usual outfit, which turns back to the grey suit in the very next shot.