rem: pref.removeObserver("mail.pane_config.dynamic", MailPaneConfigObserver); 
add: pref.removeObserver("mail.pane_config.dynamic", MailPrefObserver); pref.removeObserver("mail.showFolderPaneColumns", MailPrefObserver); 
context: function OnUnloadMessenger(){  accountManager.removeIncomingServerListener(gThreePaneIncomingServerListener);  pref.QueryInterface(Components.interfaces.nsIPrefBranchInternal);  pref.removeObserver("mail.pane_config.dynamic", MailPaneConfigObserver);  // FIX ME - later we will be able to use onload from the overlay  OnUnloadMsgHeaderPane();  OnMailWindowUnload();}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/6a51edfd023958917283a7288d9195ddf68f5d84/msgMail3PaneWindow.js/clean/mail/base/content/msgMail3PaneWindow.js