Continuity mistake: When they're all releasing the balloons the shot from behind shows no wind moving the balloons; a shot later from the front there's a very strong wind; but a shot later from a side angle there's now a mild breeze blowing.
Continuity mistake: When Judy is watching Nick sign at the Carry On-oke an Asian guy with a striped shirt behind her appears / disappears between shots.
Continuity mistake: When Judy wakes up with Steve, her left arm is either tucked under the sheet or on top of it, depending on the shot. This changes back and forth.