In the scene where Fiona and Michael have dinner with Michael's mother, the straps on Fiona's dress move up and down from shot to shot.
When Michael is searching Madeline's home for bugs, at one point Madeline's cigarette has a large ash residue on it. The next moment (before she has a chance to light a new cigarette) she has a newly lit cigarette in hand.
When Michael is in the club canvassing the club girls for information, the color of the drink the blonde girl is holding changes from red to blue and back again multiple times.
(at around 10 mins) When Michael is sitting down talking to his mother's friend in her living room, a fly lands on the front of his shirt and then disappears into thin air. It appears they edited it out half way through.
When Sam and Fiona are interrogating Quentin's henchmen on the boat, you can see the camera crew and boom mic reflected in the girl's large earrings.