does it to me in xScope also, there is a shortcut for gesture zooming, not sure if it is system or xScope based (yeah I know, who is too lazy to pinch to zoom that they need a shortcut?)
/ O \ = you touch and hold, then slide your finger diagonally to the left or right (testing it shows I can slide up or down, still does the same thing), have not found a way to deactivate it.