In the episode where Arnold and his classmates build a float for the parade, there is a stupid slip-up. Helga's father is donating money to help build the float. He is not satisfied so he hires a professional to rebuild it, they turn it into a big beeper. When Arnold's friends are riding on the float dressed up in costumes, the camera centers on Nadene and she has brown hair. Then it goes somewhere else and then comes back and her hair is blonde!!!! Somebody needs to stop screwing up!!!!!!!