Other mistake: In the scene where Drakken accidentally "clones" Bonnie Rockwaller instead of Kim Possible, he holds up a picture of Kim to compare the results of his experiment with the real thing. The Bonnie clone, completely encapsulated behind the glass of Drakken's cloning machine (as evidenced by the reflection of light off of it) somehow manages to get a hold of the picture despite this barrier. (She does this without having to break the glass.).
The Great Egg Heist/The Feud - S2-E9
Other mistake: In the Great Egg Heist, when they arrive at the museum, Jimmy gives everyone shishkabob-shaped earplugs for Libby's scream. But in the next shot, if you look at everyone's ears, there are no earplugs. Also, in the next shot, next to Libby you can see Carl putting his hands over his ears. This is impossible because the pointy ends of the earplugs would stab Carl's hands.
Other mistake: Eddie and Chelsea begin sharing notes in class. After Raven has picked it out of the trash, she reads what Eddie and Chelsea have put. Chelsea says, "Can't wait", but how could she? Eddie threw the note and it didn't reach her, just the floor, so Chelsea never read it nor make a reply.
Other mistake: Fred's shadow isn't shown in the opening credits.
Suggested correction: Be more specific. What part of the opening credits?
When their shadows are black and going across the screen from right to left.
Max's Bath - S1-E4
Other mistake: Max drinks some grape juice from the fridge, then when he takes the cup away from his mouth, the amount of juice in the cup is the same as before.