add: getCalendarManager().removeObserver(calCalendarManagerObserver); 
context: function finishCalendarManager() {    // Remove the category color pref observer    var pbi = prefService.getBranch("");    pbi = pbi.QueryInterface(Components.interfaces.nsIPrefBranch2);    pbi.removeObserver("calendar.category.color.", categoryPrefObserver);    pbi.removeObserver("calendar.", calPrefObserver);    var calendarList = document.getElementById("list-calendars-listbox");    calendarList.removeEventListener("select", onCalendarListSelect, true);}
meta: 8395	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/8395/d271fb2657c9f35b24796ae2b704e83120462f68/calendarManagement.js/buggy/calendar/resources/content/calendarManagement.js