Other mistake: When Sportacus jumps out of his blimp, his crystal is missing.
Continuity mistake: In the opening scene where Tommy and Jude are composing a song, Jude's head is turned to the side in a wide shot. In the following close-up shot, her head is staring straight up and not turned to the side.
Continuity mistake: In two episodes aired consecutively on CBBC on April 7th 2004, The "DON'T WALK/WALK" sign moves from one side of the crossing to the other and changes colour. At the end of the episode where Bernie has a lucky watch, the sign is to the right of the main door to the apartment building and has orange text. At the start of the episode where Bernie finds a cat, the sign is to the left, and red.
Factual error: When the large Dutch guy tells his story about his life in Holland, there are a several windmills. However, the blades are placed on the wrong side, that way it's not possible for a windmill to turn clockwise, which it does. If the blades were placed correctly, they would still turn to the wrong side, because wooden windmills in The Netherlands are always turning counter-clockwise.