Got a brand new installation of Freya 3.2 and steam. Have been using the external monitor (VGA) for some desktop use just fine. Tried to run a steam game on it, and it looked all messed up, part of the game outside the edges of the monitor etc. Turned off the external monitor in system settings and decided to play on my laptop's screen. Worked fine with the lower resolution. After playing I went back to system settings to re-enable my external monitor but now it doesn't work! When I click "Use this monitor" the button jumps back to Off, but the resolution field gets filled in (1920x1080). How do I re-enable my monitor for desktop use?