Oh I hate it when that happens... My younger brother has done that to me before, it was on my personal Dynasty Warriors 4 Empires saved file. We all usually have our own seperate ones but one of my brothers saved over mine "accidently" since it was the first save slot... Heh... I was not very happy >.> But then again I have had times where I accidently saved over my own saved file from a game I had finished previously. So yes... I would find that all my work to finish it was lost and that I would have to do it over with my new saved file.