Other mistake: When the clock is first shown in "Dances," the time is 7:40, but the title card reads: "1 hour 40 minutes until 9:00."
Sick Days & Spelling Bee - S1-E6
Other mistake: Vincent Martella plays a bit part as "Scoop", a newspaper photographer. His name is misspelled in the end credits as "Vincent Matella."
Computer Labs & Backpacks - S1-E9
Other mistake: In "Computer Lab," when Cookie is scanning for his locker, the exact same locker is scanned as both "Not Yours" and "Locker Located."
Art Class & Lost and Found - S3-E5
Other mistake: Ned paints a rather obscene painting and brings it up to his teacher. He had just painted the painting and his teacher gets angry at the school cutting the art budget, so Ned holds the painting against his chest. When he takes it off his chest, there is no paint on his chest and the painting had no chance to dry before he put it on his chest.
