Recently had to reformat my computer, and the Steam download was acting a little funky.
Finally says it's complete, I can go into the Steam Data files and see them all there, I have every single DLC checkmarked to launch with the game, and yet Old World Blues is absent. Dead Money and Honest Hearts work fine, Old World Blues will NOT.

Any ideas how this happened? Or any Steam experts who know where I could re-download OWB without redownloading the entire game and the other two DLCs?