After finishing the game and watching the end credits, I can't click on the arrow to bring down the menu. I play in a window, so this is no problem really.. I can just click the X to quit or whatever. I tried it in full screen as well, though, and had the same problem.. so I had to go through the alt-tab shtick to achieve the result.
Can live with it since it happens after everything is done and over.. but.. still not supposed to happen, I'll assume.