Continuity mistake: After Alex and Dan go dancing and go back to her apartment, she reaches up to get a door key from the top of an electrical box outside her door. She takes down the key in her right hand and then opens the door with her left hand. The key never goes near the lock or doorknob.
Continuity mistake: In the scene where Beth is desperately trying to find Ellen, she approaches a stopped Chevrolet Caprice wagon and rear ends it. When the camera switches to an interior shot of Beth's vehicle during the collision, the vehicle in front has changed to a Ford LTD wagon.
Continuity mistake: After Glen Close kicks Michael Douglas out of her apartment he's standing next to her bicycle holding his stuff. It can be assumed that he put the stuff on the bicycle seat because in the next shot his hands and the handlebars are empty. But later as we see him getting ready to leave again his stuff is the on handlebars. (00:34:35 - 00:37:10)
Continuity mistake: When the phone rings as Beth paints, Beth puts her roller in the tray and goes to answer the phone. When she returns the roller is in a different position than it was before.