Mac notebooks support two-finger scrolling with the trackpad. This generates mouse-wheel events. With AWT, MouseWheelEvent.isShiftDown() returns false for vertical scrolling and true for horizontal scrolling. However, with NEWT, MouseEvent.isShiftDown() returns false in both cases (though it returns true when the shift key is actually down).
This erroneous behavior exists on all platforms!
http://jogamp.org/git/?p=jogl.git;a=commit;h=da14d647581751f3d2f6d651741eaec485e255b5