axes3d zlabel fails to rotate

If I rotate an axes3D instance with a zlabel
far enough so that the ticks and label "switch sides",
but so that the xlabel and ylabel remain at the bottom,
then the zlabel does not rotate 180 degrees,
as it should to look right. (If I then tilt it so
that the xlabel and the ylabel move to the top,
it does the necessary rotation.)

Alan Isaac