I have had this a number of times when moving the mouse between monitors, the mouse cursor freezes on the transition and all control is lost, can't ctrl+alt+f1 to get to a terminal even. I can ssh into the machine and restart lightdm, but restarting just unity did nothing. I think this has happened since the stickyness or pressure between monitors got added to do with the launcher reveal.
I have had this a number of times when moving the mouse between monitors, the mouse cursor freezes on the transition and all control is lost, can't ctrl+alt+f1 to get to a terminal even. I can ssh into the machine and restart lightdm, but restarting just unity did nothing. I think this has happened since the stickyness or pressure between monitors got added to do with the launcher reveal.