I was playing Arkham City the day it came out and I had some demos downloading. As soon as the demo finished downloading the game says "New downloadable content has become available. Returning to main menu" or something similar to that. It then returns me to the start screen for the game and I had to start over what I was doing at the time. The demos had nothing to do with Arkham City and this is the only game I have ever had that did this one me.