Continuity mistake: When Ben Stiller picks up the Vapoorise to throw it in the bin, he picks it up with his right hand, but he throws it with his left.
Visible crew/equipment: When Nick flies off the merry-go-round and starts rolling on the ground we can see some wires attached to his feet. (01:16:30)
Continuity mistake: When Ben Stiller's "wife" takes the Vapoorise out of the bin and slams it down on the work surface, it has a nozzle on the top. In the next shot, the nozzle is gone.
Continuity mistake: When Ben Stiller sits down for breakfast with his family, he opens a sugar sachet, but pours the sugar out twice in two different shots.
Continuity mistake: When Jack Black and Ben Stiller are watching the baseball practice, there's a shot where the camera is behind them, and there's a lady in a pink cowboy hat sitting directly in front of them. In the next shot, shes moved to their right by about 3 feet.
Continuity mistake: Near the beginning of the movie, when Jack Black is talking about his hand, the arrangement of his tie changes between shots.
Audio problem: When Jack Black is driving the golf cart he is talking to Ben Stiller, but his lips aren't moving.
Visible crew/equipment: A door to door sales woman greets an old lady. When the old lady turns around and announces her, the lighting screens get reflected on her glasses.
Continuity mistake: When Jack Black is on the running machine, he high kicks while facing Ben Stiller. The shot from behind Stiller shows Black's first kick rising above Stiller's shoulder, yet when the angle changes the kicks that follow are below shoulder, and maintain the same height as if Black has not lost a beat or breath.