Some Like It Hot (1959)

Continuity mistake: It is supposed to be night when Joe slips out of the hotel, but a daytime sky is visible.

Continuity mistake: At night, on the train, Sugar gets the curtains stuck between the ladder and the side of the berth. In the next shot she opens the curtains while standing on the ladder and without moving it. (00:36:05)

rabid anarchist

Continuity mistake: When Tony Curtis & Marilyn are on their way to the yacht, Marilyn has what appears to be a clear 'bra-band' across the back of her gown - this band appears and disappears until they are finally settled in the room.

Continuity mistake: This takes place in the scene where Tony Curtis and Jack Lemmon first meet Marilyn Monroe on the train. Throughout the scene you can see Marilyn Monroe's black bra straps appear and disappear. It happens once on her right shoulder and once on her left shoulder. (00:28:00)

Continuity mistake: In Florida, Josephine and Daphne are assigned to room 413, but from then on their room number switches back and forth between 413 and 415.

rabid anarchist

Continuity mistake: In the scene on the train when Sugar climbs into 7A with "Josephine" she hides from Sue who is going to the bathroom. The girls come in and start a party. When it spills over into the walkway and "Daphne" pulls the brake cord, Sue jumps up from her bunk. She never came back through the hallway from the bathroom or she would have seen all the girls coming to the party.

Boobra

Continuity mistake: In the chase scene in Florida, Joe and Jerry escape the gangsters at one point by running up to their rooms, changing into their Josephine and Daphne costumes and then coming back to the elevator. The problem is that the two reside on the 4th floor in Room 413 and the elevator shows that they came down from the 3rd floor.