Continuity mistake: When Jack and Gibbs are coming out of the carriage by the palace, a soldier tosses a little bag with money to the carriage driver. In the next shot, you see the soldier tossing something to the driver again.
Continuity mistake: Near the end of the movie, when Jack is talking to Angelica on the deserted island before leaving her, you can see the gold earring in her left ear in the shot over her shoulder facing Jack. In the next shot, over Jack's shoulder, her hair is covering her left ear. Then another shot from behind Angelica, and you can see her earring again. And a final shot from behind Jack, where Angelica's ear is covered again.