Overlay missing in Window mode

When viewing a metro application in Windowed mode the overlay in the top-right corner does not show. 

http://www.filedump.net/index.php?pic=20131022103644weather1382409313.png

http://www.filedump.net/index.php?pic=20131022103801weather1382409313.png

Without the overlay, it is impossible to make App fullscreen again and difficult to access the charm bar. 

Running ModernMix 1.12, on Windows 8.1.