Audio problem: During the Tea Party scene, the Mad Hatter and March Hare ask Alice to tell her story. After the Mad Hatter says "And when you come to the end, stop!" audio follows of the voice director saying "great," leftover from the original recording. (00:45:40)
Continuity mistake: During the final dance number, Vera-Ellen's skirt alternates repeatedly between long and flowing and short and tight - perhaps to facilitate some of the dance moves.
Continuity mistake: When Jerry gets in Milo's car so that she can get cash to pay him for his paintings, they get into a dark green car. In the next shot they get out of a light (slightly greenish) blue car. (00:23:00)
Factual error: Actual showboats were very rarely self-propelled. The engine and boilers needed to propel the vessel would have taken up the space needed for the stage, backstage area, and auditorium. As a result, they had to be towed everywhere by a towboat.