I know im a few, well, many years late. However, if anybody is still looking for a solution to this issue I have one. First you need to start the SMART board calibration. You don't need to actually calibrate the SMART board, you just need the calibration overlay on-screen. Then press crtl + space to switch your active SMART board monitor. Im not sure why there is no information on this, so I'd figure I'd share. Better late than never!