--- orig/chrome/content/calendar/calendar-overlay.js	2012-02-13 20:34:09.000000000 +0100
+++ new/chrome/content/calendar/calendar-overlay.js	2012-03-26 15:57:00.471519030 +0200
@@ -68,8 +68,10 @@
     alert(bundle.getString("deletePersonalCalendarError"));
 }
 
-/* function openCalendarUnsubscriptionDialog() {
-    let calendar = getSelectedCalendar(); */
+function openCalendarUnsubscriptionDialog() {
+    let calendar = getSelectedCalendar();
+    promptDeleteCalendar(calendar);
+}
 
 function promptDeleteCalendar(calendar) {
     let url = calendar.uri.spec;