*** c:/Users/andrea/AppData/Roaming/.emacs.d/elpa/org-20140422/org.el	Wed Apr 23 22:15:51 2014
--- c:/Users/andrea/AppData/Roaming/.emacs.d/elpa/org-20140422/org.new.el	Thu Apr 24 12:40:49 2014
***************
*** 15557,15562 ****
--- 15557,15563 ----
         ((member property org-special-properties)
  	(error "The %s property can not yet be set with `org-entry-put'"
  	       property))
+        ((equal value "") (org-delete-property property))
         (t ; a non-special property
  	(let ((buffer-invisibility-spec (org-inhibit-invisibility))) ; Emacs 21
  	  (setq range (org-get-property-block beg end 'force))