I played Fallout:NV when it was released for a great many hours. Did everything, all endings, etc. The only trouble I had was the Steam over-writing quick/autosave games which was easily worked around.

So yesterday I heard about the Dead Money DLC and bought it. First Steam downloaded and installed a ~100MB patch, then downloaded the DLC.

I fired up the game, checked Dead Money in Data Files, loaded up a save game, played in the new area a bit and died (I said, “No”.. just for fun). Then when it attempted to reload it froze up. The roulette ball spun around once and sat there until I force-killed the program ten minutes later.

I repeated the process three times (dying in different ways at different points and loading from different save games). The game loads perfectly fine only one time, it will not reload without quitting the game and restarting it.