Continuity mistake: In the cinema hall, when we see the South Park kids before the movie starts, you can see what looks like a baby, who we can presume is Kyle's baby brother, sitting next to him to his right. However, at the part in 'Asses Of Fire' where Terrence and Philip are having a farting competition with a traffic police and after a couple left the cinema in disgust, the camera cuts back to the gang but the baby has disappeared. After the gang leaves the cinema 3 hours later, the baby reappears and is seen dangling on Kyle's arm. (00:04:50)
Continuity mistake: In the scene where they go to the pond after watching the movie, Wendy and her boyfriend are not on the ice, but in the another shot shortly after she skates up to Stan.