My city Kaffara just disappears.  repeatable from the linked save just play forward two or three turns (i've been using my army to clear the bandit camp during those two turns, for what it's worth)

i think it is just bugging out and disappearing.  Maybe, it's being attacked and wiped out by something i can't see?  in which case there should be a "your city is under attack" or something

afterwards it seems like i can't rebuild in the same spot, as if the fertility has gone away or something ... 

http://dl.dropbox.com/u/8021058/disappearingKaffara.EleSav