Continuity mistake: When Mr. Roper tries to explain to the girls and his wife what he was doing in Jack's bedroom, watch over Mr. Roper's left shoulder on the shelf. The number of yellow cans on the shelf keep alternating between one and two cans throughout several minutes. In addition, also notice the suitcase on the floor under the shelf as well. Whenever one yellow can is shown, the suitcase is by itself and whenever two yellow cans are shown, there is a square silver bag in front of the suitcase.
Episode 26 - S2-E1
Continuity mistake: In the episode Bert and Danny are helping Jody move a couch into his new apartment. They take a break and Danny hands Bert a beer. Danny opens the beer while Bert is holding it and it sprays over the front of Bert's coveralls. A second later, in the next shot, the beer spray is gone.
Julie's Old Flame/The Jinx/The Identical Problem - S1-E8
Continuity mistake: During dinner, when Sharon hears the kid's laugh she recalls her dead baby. Her left arm is either raised or lowered depending on the shot.