Gears of War problem (technical)

[StrainedEyes]

I was playing Gears earlier today and everything was fine.

I am trying to play it now, but no matter what single player I try to do, a screen comes up and warns me that it will overwrite my checkpoint. I click accept and it brings me back to the previous screen. It does this for new campaign, loading checkpoint, and loading previous chapter. It won't let me accept the overwrite and start playing the game..

It's very strange..