I've just setup a third monitor in portrait mode (vertically positioned on my desk). What's strange with this is that although I can manually resize a window to use all of this screen if I maximise the window it only maximises using half of the available real estate (the top half of the monitor).
I've no idea what is causing this and Google seems to reveal a lot of resolutions for this problem in OS/X but not in Windows 7 - help!