Your Home Sweet Home is My Home Sweet Home - S4-E25
Continuity mistake: The Petrie house (where Rob and Laura, Jerry and Millie are standing together bickering) is completely different from the episode "Where Did I Come From?" and a few others.
Too Many Christmas Trees - S4-E13
Continuity mistake: When Steed and Emma are driving to the estate, the car's windscreen keeps disappearing. It's there in full shots, gone in close-ups, and reappears again every time we cut back to a long shot. (00:10:30)
Continuity mistake: When Officer Dibble almost runs off the ship, he is holding his club, but when Dibble reaches the side of the ship in the next shot, the club has disappeared.
Such a Nice Little Man - S3-E29
Continuity mistake: Hazel gets a glass to pour some milk. Hazel picks up the milk bottle in her left hand and begins to fill the glass from the left. In the next shot the glass is empty and a hand is shown pouring the milk into the glass from the right. (00:02:00)