Of the 3 DLC's only the pitt worked for me with no problems, broken steel is now working after an excesive amount of effort. Op Anchourage still wont work for me.
What really bugs me is that I have to re log in to live each time Fallout crashes (frequently with DLC's) and that all the live pages treat you as an XBOX user (no I dont want the xbox newsletter). Surely if your logging into windows live it should assume your a PC user.
There are some tools that allow you to remove the need to log into live once you've installed them from live but you'll still have to use it at some time to get the content legally.