The 'X' Gomez makes on Morticia's sleeve disappears immediately after he makes it, and is never seen again.
When Gomez is looking at the ticker tape, some of it droops into a wastebasket, then is pulled out. In the next shot, it is in again. Gomez's hands on the ticker tape also change position in this shot.
Each time Lurch looks out of the window at his adoring fans, the mounted swordfish with a leg sticking out of it (Cousin Farouk/Squint) is missing and the holes in the wall are visible. The first time after he looks out of the window, the swordfish is back in it's place when Lurch sits down at his harpsichord to practice some more.
When Lurch is saying goodbye, Morticia rises from a seated position and once again the spider tassels on the bottom of her dress are missing.
When Gomez is practicing his fishing in the living room, as Morticia walks up to him, the spider tassels on the bottom of her dress are missing and her shoes are visible.