I've got 2 1920x1080 monitors, one vertical, one horizontal, I had all the windows on the horizontal one.
huh that's weird, it's supposed to move the window a bit up to show the other 2 windows, and I thought if the screen is small it would go out of the monitor, but that doesn't seen like the case...
actually just checked it should stay on the middle of the main screen, I'm not sure what happend