I have a Macbook Pro with OS 10.6.4 that often has a monitor attached. I extend the desktop to that monitor. But sometimes the external isn't connected. My Parallels 5 Windows XP VM sees the second monitor, even when it's not attached. How can I entirely disable the second monitor? The display properties show the second monitor as "attached" - even when the monitor is not physically attached to my Mac. This is causing problems in several applications. How do I detach the second monitor?