I upgraded to Ubuntu 14.04, and had tons of Unity issues (like many users, it seems). I was able to eventually get my Dash and top bar back by trying all of the various resets folks have suggested, but one thing I still cannot do is move any windows. Whether they be application windows (like this Firefox one), or file explorer windows, I cannot move them by dragging the title bar; they seem locked. I've also tried alt-space + m, and then using arrows, but nothing happens after hitting the 'm'.
I am also unable to re-size any of them by dragging a side or corner inward/outward.
Is there some hidden "lock all windows from any movement" feature in Unity Tweak Tool, or some other system setting, that is prohibiting any action?
Note that I tried logging in as a Guest, and had NO PROBLEMS there; resizing and movement worked fine, so it seems to be specific to my local user account.