Continuity mistake: In the movie "Channel Chasers," when Timmy and Vicky go into Maho Mushi, Timmy gets a piece of his hat sliced off and Vicky gets the tip of her ponytail sliced off. But in the next shot, they're both back to normal.
Fairy Friends and Neighbors/Just the Two of Us - S4-E11
Continuity mistake: When we first see Trixie and Timmy inside Timmy's large sand castle (or whatever it was), they were sitting at the ends of a long table. But when Francis destroys the castle, Trixie and Timmy are way closer together.
Continuity mistake: In the TV movie, "Channel Chasers," Vicky makes herself 18, changing the shape of her body. But later there's a brief shot of her in the place where you can get into any channel, and her body's the same as it has been in any other episode. But later she goes to face Timmy and she's 18 again.
The Big Superhero Wish - S4-E3
Continuity mistake: I don't remember if it's this episode or not... When Timmy opens his locker and finds a stack of papers, and they fall on him, they multiply to fill the whole hallway.
Continuity mistake: When Timmy first finds the place in the license plate maker where you stick letters in, there were 7 slots, but later when we see him spelling "I wish I was ten", there are 12 slots, enough to fill in that sentence, without the spaces.
Vicy Loses Her Icky / Pixies Inc. - S4-E4
Continuity mistake: When Ms. Waxelplax tries Timmy's homemade golf course, her ball hits a windmill, knocking it loose. The windmill flies forward like a propeller but on the next cut, flies sideways.
The Big Superhero Wish - S4-E3
Continuity mistake: Probably around the time when Elmer (kid with boil) the normal kid bends the Baby Shredder (Vicky's) claws, the boil jumps from one cheek to the other, and Elmer's making it do that.
Vicy Loses Her Icky / Pixies Inc. - S4-E4
Continuity mistake: When HP does his ball for hole 1, it flies up, and falls diagonally, but at the next shot, it falls vertically.