In Juce 4.1 (OSX, non-retina display), whenever I press the mouse, a mouseDrag event is being fired, even when the mouse hasn't moved at all. "Moved at all" being defined as common-sense perception and also MouseEvent.getPosition() returning the same values for the mouseDown() and mouseDrag() events that are both fired. I did not have this problem in 3.2.
One addendum .. mouseDown and mouseDrag locations are also identical on the MouseEvent.position.getX()/getY() level .. at least to the resolution of printf %f: