Vampire Bats and Scaredy Cats - S2-E2
Continuity mistake: When Lisa's uncle shows her her grand-father's picture, it changes from one shot to another.
Diana Ross - S4-E23
Continuity mistake: When Diana Ross finishes her first song, the bird has both his feet on the ground; in the next shot, the bird has one leg raised, without enough time passing to do so. (00:08:45)
The Robbery - S4-E4
Plot hole: Towards the end, Jake (Shirley's boyfriend), hangs the girls on a coat rack by the hoods of their coats. They try a few comical ways of trying to escape, when they could have simply unbuttoned their coats and slip away.
Continuity mistake: At the beginning of the episode, as Mat enters the kitchen with a chicken in the newspaper, the attentive viewer may notice a small shelf on the wall. At first there is only salt on the shelf, but when Mat is about to put the chicken in the oven, suddenly an orange mug can be seen on the shelf next to the salt, which was not there before.