What happened to my game???

This is dumb...

I updated my 360 to the fall update and everything has been working fine! No issues. Until I play Assassin's Creed. My game now plays widescreen...it did not do this before the update. It was full screen. And my console is set to NORMAL for a setting. It doesn't do this for any other game...

P.S. Oh yeah, I have a standard TV, and I can't afford to get a widescreen TV. If I have to play it widescreen with the black bars, I will, but I'm just trying to figure out if this is a part ofa bigger issue...