The crosshair rotation does not work any more, if one plane is rotated in a way it is congruent to a nother. Even a Reinit or GlobelReinint does not help.

-Enable crosshair rotation
-rotate one of the plane so it is fitting the other

e.g. in the transversal window rotate the
coronal plane (blue line) so that it fits
the sagittal (green line)

-release the mouse button
-now try to rotate again
-perform a reinit and try to rotate

Seems that the picking of the plane is some kind of confused. If two planes are concruent it should be possible to pick at least one of them.

Note:
3M3 shows the same behavior