Hi, I have a 27" i7. I have a 24" DVI Montior hooked up to it via MDP->DVI adaptor. When the 24" Monitor is on, everything is fine. When I turn the monitor off, the magic mouse tracking on the 27" screen stutters. I am not kidding - it took me ages to figure out that to fix I either need to turn the other monitor on OR disconnect the MDP->DVI adaptor. Any help? Is there an app that lets me disable the external monitor or a sudo command to do it? Or turn off the MDP output altogether?