Continuity mistake: When Molly takes Mikey into work and he is under the desk, Rona is still wearing her shoe. Yet when the scene changes, her shoe is missing when Mikey starts tickling her foot. Then when the boss realises that Mikey is under the desk, her shoe is back on. When the shot changes again, her shoe is off.
Other mistake: In the scene when Mollie, James, Mikey, and Julie are in the restroom together, Mollie tells James (who was shaving) to hold Julie while she explains something to Mikey. While James reaches down to grab Julie, he has shaving cream on his upper lip. But, when he comes back up, the shaving cream is gone.