sfrose -- I had this happen in one of my villages too, only I haven't finished any collections in that village. Usually, after I finished the puzzles, I lower my speed to 1/2 time so I don't have to rebuild the fire so often. Well, when I discovered that my population was aging, I bumped it up to x2 so they'd die quicker (I'm a heartless guiding hand) and my parents could re-populate slowly.