
Plot hole: There are six metal bars mounted around the circumference of the water wheel's axle. In the wheel's interior, when Jack frees himself he lands on his feet, begins to run and promptly hits his head on one of those mounted axle bars, then falls out. Moments later, when Jack returns and runs in the wheel, he is shorter (way more than a foot) than all six of the mounted axle bars spinning with the water wheel, which would make that previous shot impossible, however humorous it is. (01:52:40 - 01:53:55)
Answer: There is a scene after the credits of "The Curse of the Black Pearl": the monkey got back to the cave and took a coin. That way he turned undead again.
Bjoern_Buller