Audio problem: During the scene with the "flying" letters Harry gets one letter and tries to go in his "room", but Uncle Vernon grabs him. When Harry yells "They're my letters," not only his mouth doesn't move but his voice sounds much deeper than in the rest of the movie (it sounds more like his voice in Chamber of Secrets). This indicates that this line was overdubbed long after the main filming, when Daniel Radcliffe's voice has already begun to change. (00:11:55)
Audio problem: On the first level of the video game, after Velma brings up what she remembers what Eric said about the Scooby snacks in the game, you hear Daphne talking but you see Velma's lips moving. (00:01:00)
Audio problem: When we see Mike during the slumber party, we hear seven bells ring for the seven filled cylinders, but there are only six cylinder-filling noises. (00:16:50)
Audio problem: When Fontana says "He's such a show-off" to her friends Lana and Anna at the beginning of the movie, her mouth doesn't move.
Audio problem: When Ash and his friends arrive at the waterfall, Mr. White speaks, but his mouth does not move. (00:16:27)