Okay, so, you don't know me, I found your journal as I was chasing fic, but anyway;

The monkey is undead through his own fault. There's a scene at the end of the credits of PotC where he swims back to the island and takes a one of the coins, making him undead again.

The other thing is, the monkey stares at Barbosa in passing as it goes for the treasure, and then does not put the coin down. Presumably, he gave it back to Barbosa, and said pirate "woke" up. And that is how he is still alive. :)