I'm trying to change the window snapping behavior in Unity (14.04) using the Tweak Tool. The Window Snapping section of the tool is available, and all the options are available (not greyed out). I make the changes I want, but the actual snapping behavior doesn't change. For instance, I set the bottom screen edge to "Bottom Half", and then drag a window to the bottom edge and nothing happens. Closing the tweak tool, logging out and back in, and even restarting the whole computer don't help. After making a change, if I close and then reopen the Tweak Tool, the change persists. It's simply not reflected in the actual snapping behavior.