add: pref.removeObserver("mail.showCondensedAddresses", MsgHdrViewObserver);  
context: function OnUnloadMsgHeaderPane(){  // dispatch an event letting any listeners know that we have unloaded the message pane  var event = document.createEvent('Events');  event.initEvent('messagepane-unloaded', false, true);  var headerViewElement = document.getElementById("msgHeaderView");  headerViewElement.dispatchEvent(event);}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/bd9553c285b5d9b3b1db06b4bb71f1a2e20904f7/msgHdrViewOverlay.js/clean/mail/base/content/msgHdrViewOverlay.js