Wtf?

[NameTaken69]

Ok, so I rented this game back when it came out and finally bought it yesterday. I start the game up today and my saved game is gone. I checked in system memory and my save file is still there, all my stats and money are also still in the game, I just can't start from where I left off. WTF? I've changed my gamertag since I rented it but I've never had this problem before.. anyone know what's up?