Comment 46 for bug 1158161

I'm using Ubuntu 13.04 (with Unity). The following steps causes the same problem for me:
1- Maximize a window.
2- Minimize the window using the minimize button in its titlebar.
3- Do not click anywhere! By moving your mouse on the titlebar, you can see that its still there and menus appear while the window is minimized.
4- Click on the restore window button. The window restores (but not in maximize mode) and you can not use its titlebar to move it nor can close, minimize or maximize it.

To fix the window, move it using alt + dragging it to the top of the screen to maximize it.