Okay so here's my setup: I have a 2009 Mac Mini connected to a 22" LG monitor via Mini-DVI port and it's also connected to a 50" Pioneer Plasma (in the next room) via Mini-Displayport. Everything works perfect except that when I turn off the Pioneer Plasma, my mouse can still scroll over from the LG monitor to the Plasma. I've also noticed that my screensaver is laggy even when the Plasma is turned off (usually that happens when it's drawing the screensaver on both screens) so it must still be sending a video signal out of the Mini Displayport. Anyone experience this problem? Why does it do this?