Continuity: Position of crashed cars after the hamsters escape.
Continuity: The writing on the blackboard.
Continuity: Reggie's hairstyle after taking off his hat in the club "The Scream."
Continuity: In the first scene involving Buddy Love driving the Viper, you can see someone sitting in the passenger side as he drives away.
Continuity: In the second scene with Buddy Love driving the Viper the passenger side seat is occasionally empty.
Crew or equipment visible: When Carla runs out of the tent after the professor, the battery pack for her mic slides down her leg.
Continuity: Professor Klump's hand and body placement when putting food in the microwave after getting a date with Carla.
Revealing mistakes: Klump returns home after getting a date with Carla and puts a frozen dinner in the microwave. The frozen dinner has an aluminum foil cover that Klump does not remove, but there is no evidence of the sparks that would result.
Continuity: The position of the Snickers wrapper that Sherman tosses into the wastebasket.
Continuity: During the first dinner scene, in the wide shots of the Klump family, Grandma Klump has a coke to drink instead of water. This happens twice.
Audio/visual unsynchronized: Drummer clearly not playing along to music at the ball near the end.
Audio/visual unsynchronized: At the end of the first family dinner scene, the camera cuts back and you can hear Ernie Jr. continuing to laugh loudly, but it is obvious by looking at him that he is not laughing.
Continuity: When Buddy and Miss Purdy go to Scream for the first time, it appears that their table is almost directly opposite the front of the stage. When Buddy later plays the piano on stage and sings to Miss Purdy, he is facing to the left of stage (ie. not in her direction). If he wanted to face her while playing the piano, his head should be turned to his right rather than looking straight ahead.