Yes, I play Steam version, and it is probably something steamworks-related.
But for me that problem was rather rare and minor - re-loading a saved game worked just fine.
P.S. I am on Windows 7 x64.
And just remembered that I had the same problem with Gemini Rue on Steam as well! Also on rare occasions, and only when loading a saved game, never with the new game like lWTD.