Index: lams_central/web/includes/javascript/groupDisplay.js
===================================================================
RCS file: /usr/local/cvsroot/lams_central/web/includes/javascript/groupDisplay.js,v
diff -u -r1.8.4.1 -r1.8.4.1.2.1
--- lams_central/web/includes/javascript/groupDisplay.js	13 May 2009 14:14:11 -0000	1.8.4.1
+++ lams_central/web/includes/javascript/groupDisplay.js	9 Jul 2009 07:27:46 -0000	1.8.4.1.2.1
@@ -74,6 +74,10 @@
 						success: function(html) {
 							jQuery(courseBg).append(html);
 							registerToolTip(this);
+							// unregister and re-register thickbox for this group in order to avoid double
+							// registration of thickbox for existing elements (i.e. group 'add lesson' link)
+							$('a.thickbox'+jQuery(courseBg).attr("id")).unbind("click");
+							tb_init('a.thickbox'+jQuery(courseBg).attr("id"));
 						}
 					});
 				}