I started the American campaign, but every time I try to save over my saved game it doesn't seem to work. After playing through about 10 minutes and saving every few turns, I reloaded the game and it was back at turn one. All I can think of is that I accidently saved my first play through as real-time, but then restarted as turn based. I have been using the same file name to override the file, but I guess its not working.