Experimantal-3027: drawing the interface bug

Windows 7, tiles

when the game is fullscreen and the resolution is not optimal (800x600 for example on my 1366x768 screen) and you ALT-TAB it you can see the interface is not drawing properly. Just try

You can see such a problem when the game is not in fullscreen too. It is when the screen have to redraw, for example when you call to a CTRL-ALT-DEL in Windows7 and then go back you can see the same problem.