Corrected entry: When Kat is in the Up and At Them she gets toothpaste and shaving cream on her. When she arrives in the lab not only is her face clean but also her dress. There is no way that she would have been able to clean her dress, even if she managed to clean her face.
Corrected entry: When Kat's dad is fighting the 3 ghosts in the beginning, one cuts off his pants. Right after, when he gets the plunger, they're back on him again.
Corrected entry: In the beginning of the movie, when Kat meets Casper, his hand goes right through hers, indicating he wouldn't be able to hold onto flesh without going through it, but there are plenty of time during the movie where the ghosts hold onto people. Casper is even able to fly while dangling Kat.
Corrected entry: There is a scene where Kat and Casper are talking in Kat's bedroom. Kat is sitting at her vanity brushing her hair and Casper is sitting on her jewellery box. They are talking about why Kat won't take Casper to the Halloween party. Casper asks what the other guy has that he doesn't. One thing Kat says is that the guy has a reflection. Casper looks in the mirror and he doesn't have a reflection. The thing is, neither does Kat. She is sitting right in front of the mirror and yet you don't see her reflection.