The behaviour is button. but using your tool drives me crazy, because if I click the right mouse button and push the mouse, it fine and I can use it - same as before.
But everytime when I click the left mousebutton and push the mouse only 0,5mm on my table, the 3D view is completely turned over and I need to use one of my saved camera-positions to be able to come back to the same view-point...
For me it would be fine, if left and right buttons could be changed ( but only for this pan-tool, not generally in windows)
But I guess it´s on me, because no other has written such a "problem"
