I mayhap have seen POTC too many times (no, not possible or probable) since I seem to have gone into analyze mode. OK, the credit scene shows the monkey taking a cursed coin. Now, if someone came along that knew about the curse and was just going to take a coin and use it to be invincible for a while (like maybe Jack took it to go and save Will) not knowing that the monkey took a coin, when Jack returned his coin wouldn't he still be cursed since a coin was still missing? Interesting.