(at around 58 mins) At the sing-off, when the Chipettes are singing, Ian uses his phone to make a video. He says "If you like what you see, call Ian Hawke...." however, when the video is seen on a website by some record executives, Ian says "If you're interested..."
(at around 1h 21 mins) At the end of the move, the chipmunks and the chipettes all say goodnight. All but Alvin, who then fusses with Dave with the lights. When Dave switches it off, Alvin switches it on, then Dave switches it back on. The camera switches back to Alvin and somehow the switch is "magically" switched back up.
(at around 10 mins) The chipmunks were spinning in the the bowl on the food processor and they flew out, the phone rang and they answered it. Somehow in between the time they flew out and they answered the phone, the food processor is turned off, but no one went back to it to turn it off.
(at around 10 mins) While the chipmunks are spinning in the bowl on the food processor they start spinning counter clockwise, then the shot switches to a close up and when it switches back to the wide shot just before they are thrown out of the bowl, they are spinning clockwise as they are thrown out of the left side of the bowl towards the hanging pots and pans.
(at around 58 mins) At the sing-off, when the Chipettes are singing, Ian uses his phone to make a video. At the end, he winks to his phone. However, when the video is seen on a website by some record executives, Ian does not wink.
(at around 15 mins) In the first classroom scene, when the girls run up to meet the chipmunks, the camera shows two students sitting behind Ryan and Xander. The camera cuts and shows the men have switched places.
(at around 5 mins) Jackie Seville referred to Toby Seville as her grandson, but he later (at around 47 mins) referred to her as his aunt. This was actually not a mistake because Toby was talking to Dave Seville at the time, and he was describing her from Dave's point of view.
(at around 1h 14 mins) When Ian is controlling the toy helicopter with the chipmunks on it, he suddenly trips and the controller flies out of his hand. While in the air, it suddenly shrinks enough for one of the chipmunks to catch it. Once one of the chipmunks catches it, it is small enough to fit on Ian's fingertip.
(at around 19 mins) When Ian takes the Chipettes to the roof they perform for him on the Jett Records sign. The sign at the very edge of the building facing the parking lot. As Ian sits on the roof and watches the girls, the sign can be clearly read, but as it is three dimensional made of stylized, cut-out chrome letters, it would be backwards when viewed from the street.