Continuity mistake: In 'The Grass...,' when Timmy is juggling a bear, the bear wrestler, and the lead carny, there is a close-up of the lead carny as he flies past the camera over and over, yet you never see the bear or the bear wrestler fly past the camera.
Continuity mistake: In the scene when the Sleep Fairy shrinks while talking to Timmy, he measures himself. The ruler says three inches. Then he shrinks down to two inches. The camera cuts to Timmy. Then it cuts back to the Sleep Fairy, who quickly discards the ruler. If you are fast enough, you'll notice that the ruler says he is three inches again.
Continuity mistake: Beddy Bye- In an early scene, Timmy's parents are watching "Up Late in Dimmsdale." In a later scene, when Timmy is featured on the show after they've run out of guests, the sign behind him is "Late Night in Dimmsdale" instead of "Up Late in Dimmsdale" like it was before.