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I have Sim's Castaway 2.

I don't see anything about chiefs.. but I do know that it will not give you another goal to do in Castaway 2 unless you have fully completed the last one, so check it out again to make sure that the last goal is fully completed.

Im not sure why, but contact the SIMS 2 Site via e-mail, or if u still have the recipet and your 28 days or whatever hasnt ran out ask fr another copy other than that i have no idea. xx

I dont have the game but I think You just beat it