Audio problem: After Han goes to the command centre during the battle on Hoth, Leia says to a controller, "Send all troops in sector twelve to the south slope to protect the fighters," but the words don't match her lips. (00:30:35)
Audio problem: When Luke and Vader are fighting in the carbon freezing room, at one point Luke forces Vader off the side, looks around, then jump down himself to look for Vader. Listen to the sound that is supposed to be the sound of Luke's feet hitting the ground; you can see Luke stand back up after jumping over the side in the bottom left corner of the screen, but Luke is almost full stood back up when we hear the sound of his feet hitting the ground.
Audio problem: In the carbon freezing chamber, Han says to Chewbacca, "The Princess - you have to take care of her". When he says, "You have to take care of her", his head is shown from behind, but the motion of his jaw doesn't match the words.
Audio problem: When Han punches Lando, his hand never makes any contact with Lando's face, and the sound effect is heard after his hand goes past it. (01:29:20)
Audio problem: When Lando is punching desperately at the door's control panel in Cloud City, he says "The security code has been changed!" but his mouth doesn't move when he says it.