Audio problem: Bruno's mouth is out of sync when he says "I really do hate margarine," as he is talking to the waitress about what are in the sandwiches that day.
Audio problem: When Mr. Stringer says "What the devil," as all of the sheets of paper on the reception desk start flying about, his mouth doesn't move.
Audio problem: Near the beginning, after Erica disappears and Helga visits Erica's mother, Erica's mother says "Come on in Helga, have some cake", but she is clearly saying something else.
Audio problem: When Luke (as a mouse) finds Formula 86, we hear him say, "We got it, Grandma," but his mouth doesn't move.
Audio problem: When Miss Irvine is sitting the room alone after being ejected from the banquet, she says that she never wanted to be one of them but her mouth doesn't move. (01:17:31)
Answer: We've already witnessed Bruno being turned into a mouse so there's no need for us to see Lukes transformation as we already know how his transformation is going to be.