Early in the movie, when the three boys (Gordy, Teddy, and Chris) are in the tree house playing cards, Vern knocks on the door to come in. As he's climbing into the tree house through the door in the floor, watch Vern's mouth and listen to the words that he says. The movement of his mouth does not fit the words that he says!
Good catch.
I remember seeing that too the first time watching that movie.
Never thought about that again.
I think that maybe I thought he was swearing or something, and it was one of those cheap TV voice edits.