I tried that but it didn't work. I have found out that when you first start the laptop everything's fine, it's just after you close the lock the laptop then unlock it (closing/opening lid) that the windows suddenly have a gap at the top where the desktop peeks through (the three buttons (close, maximise, taskbar-ise) are still visible, the window is just shorter).
Infact, if the window is fine (after starting up), and I drag up the taskbar to the top of an open window, the window gets smaller and has a gap.