I don't know if anyone else has had this experience, but I found a major bug/exploit when negociating peace. When Japan offered me peace for $90, I demanded all of his cities except for his capital, all of his techs, and that he convert. He did not accept this, of course, and was SUPPOSED to give a counter-offer. The surprising thing is that his counter-offer was EXACTLY the same as what I had demanded. So I got all 5 of his cities and all his techs. Try this exploit if you're desperate. I'm sure they'll fix it in the first patch.