add:  this._destroyed = true; 
context:   uninit: function ()  {    var os = Components.classes["@mozilla.org/observer-service;1"]                       .getService(Components.interfaces.nsIObserverService);    for (var i = 0; i < this._messages.length; ++i)      os.removeObserver(this, this._messages[i]);  },
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/bea8454b205f7120e28765dc8aca7db388284c22/update.js/clean/toolkit/mozapps/update/content/update.js