Unable to delete Note on contribution status

From the forum: http://forum.civicrm.org/index.php/topic,2572.0/topicseen.html

It is inpossible to delete a previously made Note on a contribution.
It ís possible to change the note, but if I delete its values completely (or change it to a space) it ignores the change and reverts back to its last note.

Try emptying the note to see what I mean:

http://drupal.demo.civicrm.org/civicrm/contact/view/contribution?reset=1&action=update&id=13&cid=104&context=dashboard&subType=4