I've been having this problem lately with Arma 2. I don't think the game is running at the correct resolution settings. Every once in a while when I start the game up the menu is fuzzy and unclear, definitely not the resolution I have it set at which is 1280X1024 (19" monitor :/ ). I think this mismatch makes its way into the game because it doesn't seem as clear. I can easily tell the difference when it works because I can see the soldiers face much more clearly on the startup screen, and in game. I've tried opening and closing the game, but today it wouldn't work.
Could it be because I have the -nosplash parameter?
I am running the Steam version.
Also, this also happened with Empire: Total War, but just a game restart and it would fix it. I think it has something to do with Steam, but I could be wrong.