Continuity mistake: Following Rodney's step from the escalator on the red pedestal he is being scooped into one half of a wire-frame globe/ball. Two halves now (the other one has Fender in it) form an intact globe. A safety bar with a 'wooden' middle bit (like those on rollercoasters) suddenly appears. After their journey, when the ball splits back into two halves, the safety bar, which previously had mysteriously appeared, now has disappeared.
Continuity mistake: When Wonderbot shows his skills in the kitchen, the number of plates he handles changes from shot to shot. First he adds 6 to the 3 plates already in Rodney's father. After cleaning only 6 plates come out. Wonderbot takes them, but the next shot shows him with 8 plates. Then he puts 5 dirty plates in the dishwasher; after cleaning these are suddenly 12 plates.
Continuity mistake: When Rodney steps on the escalator (a giant metal wheel with escalator steps), in the station of Robot City, you can see another robot standing on the step above him. In the next shot Rodney gets from the step on top of some sort of red pedestal. The robot on the step above him has now disappeared.
Continuity mistake: When Rodney and Cappy enter Bigweld's home, you see several shots of the dominoes used in the taping of the Bigweld show sitting on the table in the workshop. The problem is, those are the only dominoes in the shot. The floor around the table is well lit and clear. From every angle the table is shown, there are no dominoes anywhere on the floor, or even leading to the edge of the table. The dominoes that continue the chain that brings Bigweld out of hiding don't show up until Rodney knocks over the first domino.
Continuity mistake: When Rodney is at the Bigweld Ball, he starts pulling his disguise off. When he is saying "to tell Bigweld that YOU...", he pulls some junk off his arm and thrusts it into the air. When the shot changes angle, his arm is not in the air and the piece he pulled off his arm is missing.
Audio problem: During the scene where Jack Hammer is sold out, the 'bin robot' says 'Hey, isn't that the guy that fixed Fender's neck?' Next someone in the crowd says 'Yeah, that g-ixes bots!' The phrase should be 'Yeah, that guy fixes bots!' There seems to be a half-second clip that is missing in the film.
Continuity mistake: When Rodney is at the Bigweld Ball, he starts pulling his disguise off in front of Ratchet. Notice the junk on his arms. When he is saying "to tell Bigweld that YOU.", he pulls some junk off his arm and thrusts it into the air. When the shot changes angle, his arm is not in the air and the piece he pulled off his arm is missing.