Same as Arimahn, excepting I didn't buy Legacy of Rome yet.
I am playing the game on Steam, Win7 64bit home, and since the update today, my DLCs, although showing up in the launcher, don't seem to work in-game (the 2 easiest to verify are the ruler designer and Sword of Islam, both are telling me I don't own them in the tool tips on the province selection screen).
I tried unchecking them and checking them again, but it didn't make a difference.
I tried deleting the DLC signature file : it is created again, with the exact same string of characters inside it.
Thank you for this most wonderful game, and I hope I can get it running again in all its glory again soon!