I reproduced. How strange. Also: It doesn't matter what Pixel/Mouse Coord Mode is chosen. Three-monitor setup: the same thing happens on my left and on my right monitor. (Edit: both place the mouse 1 pixel too far to the right.) Thing is fine on my central (and main) monitor, works like a charm. If I check the AutoIt Window Info tool, I see that the coordinates on the left monitor are negative, but that isn't the thing apparently, given point 2 (it also fails on right monitor, with positive x