Comment 11 for bug 971147

Doesn't seem to depend on drivers or Unity, rather on Compiz.
As described in
http://askubuntu.com/questions/576604/what-causes-the-deviation-in-the-wmctrl-window-move-command
both xdotool and wmctrl report the correct (inner) position of the window, but for moving use the decorated (outer) size.

For example, this should leave a terminal window at exactly the current position:
xdotool windowmove --relative `xdotool getactivewindow` x y
But instead it moves it by the decoration size, which you can find out with xprop looking at the _NET_FRAME_EXTENTS(CARDINAL) variable
In my case,
xdotool windowmove --relative `xdotool getactivewindow` -1 -28
leaves the terminal window at the current position.

This would be solved if we could move the window with -100 further to the left (so the decoration part is off the screen), but unfortunately there seems to be a hard gap blocking it.