When Norbit is talking to the girl that he likes at the fair, one of the kids (a young girl) riding on the merry-go-round is seen watching their conversation and is instructed by someone off camera to look away.
When Mr. Wong throws the flagpole/spear at Rasputia at the end of the movie, he appears to throw it backwards (the pointed end is facing backwards when he throws it). The next shot shows the point flying forwards before hitting her.
Near the end of the movie, a close up of Rasputia has a Tennessee Post Office in the background. The zip code is 8xxxx, which would normally indicate a post office in the Southwest. Tennessee zip codes are 3xxxx.
When young Kate is adopted the guardians pick her up in the silver car. When she's looking out of the back window to say goodbye to Norbit Its obviously that there is no glass window on the back of the car. There is no reflection from the window, while the sun is reflecting off the car.