I had my Venice window out of focus because the game was on a strangely long "loading" screen. Came back to this: http://i.imgur.com/8qSXbvK.png - the client was animating and sounding, but the OK button could not be clicked or keyed. Alt-F4 still closed the game correctly.
Would something like this be better reported in the tracker, or is this alright? I don't have a GitHub account, but I guess I could make one for this if necessary. I apologize if this is already a known bug.