rem: var pbi = pref.QueryInterface(Components.interfaces.nsIPrefBranchInternal); 
add: var pbi = pref.QueryInterface(Components.interfaces.nsIPrefBranch2); 
context:   shutdown: function()  {    try {      var pbi = pref.QueryInterface(Components.interfaces.nsIPrefBranchInternal);      pbi.removeObserver(this.domain, this);    } catch(ex) {      dump("Failed to remove pref observers: " + ex + "\n");    }  },
meta: 5459	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/5459/361daac9367ad464688c4da3c3206d18cb2ae94e/editor.js/buggy/editor/ui/composer/content/editor.js