I have a recent mac book pro and elements 11. I have a problem using the Clone Stamp tool, if I have a bluetooth mouse connected I can alt click then hold the left mouse button down and paint by moving the mouse. If i revert to the Mac trackpad I can alt click to select , then When I hold the pad down to click it just leave a single point of colour but won't let me drag the selection to paint. How do I paint using the trackpad please