Continuity mistake: When Lasky heads toward the conning tower, an A-7 Corsair is shown at left (and the helicopter nose has a number "3" on it). As he is led inside the tower, the camera pans up, and now the Corsair is gone, replaced by an E-2 Hawkeye (and the number "3" on the heli is gone, too). (00:06:45)
Continuity mistake: When one of the stormtroopers unties Han Solo before he is put into the carbonite, watch his wardrobe - he has a disappearing / reappearing jacket on. This is fixed to an extent on the DVD - the jacket is now lightened to almost match his shirt, but it's still shiny like leather. (01:32:05)
Suggested correction: It just looks like a jacket because it's a shadow.
Continuity mistake: There are a couple of instances in the movie where the models do not correspond with the actual sets. When Klytus arrives at the Hawkmen city he lands near the top of the city. Yet in that very hall there is a pit with a deep void underneath. Such a room could only exist at the bottom of the city. Also, when the Hawkmen start to land on Ajax, its engine section appears to be missing. (01:10:10 - 01:14:30)
Continuity mistake: There is a scene in which it is raining quite heavily and Em and Richard are inside the hutch. Richard is playing Pop Goes The Weasel over and over which annoys Em. She stabs him in the foot and he chases her outside. In this scene she is wearing a strapless dress but when he catches her and pins her down on the sand she is wearing a lacey jacket (she didn't have time to change) and there are no clouds or rain. The sand doesn't seem to be very wet either, despite the fact that it was raining heavily a few minutes ago. (00:41:10)
Visible crew/equipment: When Superman is fighting Non under the New York Streets (in the sewers), manhole covers start to jet up in the sky. When the first manhole cover shoots up you can quite clearly see the gas tube in the hole and the gas cylinder attached to the cover.