Index: lams_central/web/ckeditor/plugins/image2/dialogs/image2.js
===================================================================
diff -u -r43cbdc5019e81e9a5f9d4c97be6be82233ade78a -r575fd3c509a8e606ca420e782eaefaf4c40e02e2
--- lams_central/web/ckeditor/plugins/image2/dialogs/image2.js	(.../image2.js)	(revision 43cbdc5019e81e9a5f9d4c97be6be82233ade78a)
+++ lams_central/web/ckeditor/plugins/image2/dialogs/image2.js	(.../image2.js)	(revision 575fd3c509a8e606ca420e782eaefaf4c40e02e2)
@@ -39,7 +39,7 @@
         
     	//remove obsolete classes
         for (var oldClass in oldClasses) {
-            if (oldClasses.hasOwnProperty(oldClass) && userEnteredClasses.indexOf(oldClass) > -1) {
+            if (oldClasses.hasOwnProperty(oldClass) && (userEnteredClasses.indexOf(oldClass) == -1)) {
             	widget.removeClass(oldClass);
             }
         }