Revealing mistake: When the chipmunks and chippettes and getting ready for the balloon race, Jeanette walks up to Simon and asks him what route to take to Bermuda. Pay attention to Theadore; he's supposed to be in front of Simon handing the chest of dolls to Alvin who is in the hot air balloon. After handing him the chest, he dusts his hands and moves his head a little while doing it. If you look at his head, it seems to cross behind Simon's even though Theadore is supposed to be in front of him. Simon's face may have needed to be seen, but still a mistake.
Continuity mistake: During the "rock n' roll" musical, around the end, the boys are dancing and are saying, "Yeah we're the boys of rock n' roll!" As they're doing this, the chippettes are already on the hot air ballon, dancing at the edges while holding the ropes and singing. If you look at the left of were Britany is, Jeanette is dancing there with her back turned. However, when it closes up on Britany saying, "Better be believin' that we are!" Look at that same spot where Jeanette was. She is no longer there.
Continuity mistake: During the car chase sequence involving Jamal's cruiser and Klaus & Claudia's Rolls Royce, the Rolls Royce makes a narrow escape at the intersection's red light. Jamal can't get through in time so he skids to a stop, leaving behind no tire tracks on the pavement. In the next shot, however, two pairs of skid marks are now visible right where they should be (although one frame too late). (01:08:35)ryguy_1983
Continuity mistake: Mario initially has a tie wrapped around his neck in the scene where the Chipmunks and Chipettes are being forced into Klaus and Claudia's Rolls Royce. It's also worth mentioning that Mario's hands are tied behind his back. Pretty soon the car swerves head-on into a pole. In the following shot we see Klaus, Claudia and Mario lying on the floor disoriented - but now he's sporting a bow tie instead. (01:07:50 - 01:09:40)ryguy_1983
Other mistake: Before the Chipmunks and Chipettes begin their hot air balloon race, Klaus goes through the rules explaining that each team will be given the opposing team's doll when they reach various destinations across the globe. He then walks over to the Chipettes and hands Jeannette a trunk full of Chipmunk dolls - but they're not supposed to receive any Chipmunk dolls until the race is in progress. (00:14:35)ryguy_1983
Continuity mistake: When Eleanor is trying to feed the ailing baby penguin with a spoon, it refuses to eat. So she places the spoon near two bowls at her side. In the following shot Eleanor can be seen dipping a rag into one of the bowls - but now her spoon is nowhere to be found. (00:54:00)ryguy_1983
Continuity mistake: When Miss Miller is pulling items of food from a cabinet, the Chipmunks are busy having breakfast. There is a carton of milk on the table right between Alvin and Simon's bowls of cereal. But after a shot of Theodore indulging in his meal, the milk carton is gone. Now Alvin and Simon have two glasses of milk instead, and who knows how they got there because Miss Miller was too busy talking to herself on the other end of the kitchen. (00:11:50)ryguy_1983
Continuity mistake: When the Chipmunks and Chipettes are approaching an airport in their hot air balloon, Simon reaches over the side and shouts, "We're home!" Notice how he and Alvin are wearing regular long-sleeve blue and red shirts respectively. But in the next shot when Dave's plane draws near, they're now wearing exotic clothes from their trip around the world instead. (01:05:35)ryguy_1983
Continuity mistake: Right before each balloon takes off for the race, Sophie is seen gnawing on a rope and behind her - on the grass next to the Chipettes' basket - a couple of wooden crates are visible. But in the following shot where the teams are in midair struggling to maneuver their balloons, no crates can be seen anywhere on the ground below. (00:15:35)ryguy_1983
Continuity mistake: When the Chipmunks are delivering a Chipmunk doll in Venice, Simon holds a Simon doll in the long shot. When the cap of the post in the water is lifted, Simon inserts an Alvin doll.
Continuity mistake: After trying to entice the primitive tribe with flashy clothes and a boom box, Alvin and Simon get tied to a hut. The four ropes around their wrists are initially tied together in one knot right above their heads. But once they notice that Theodore is being pampered like a god, Alvin and Simon's wrist ropes are suddenly knotted separately instead. (00:51:05)ryguy_1983
Continuity mistake: When Clause and Claudia are pushing Alvin and the rest into their car at the end, Alvin is seen without his cap. You then see a shot of the inside of their car, and in the next shot Alvin's cap magically appears on his head and blows away. His cap is still off until after he hugs David at the end, then it's back on his head again.