rem: button.accesskey = strings.getString(aButtonKey + "Accesskey"); 
add: button.setAttribute("accesskey", strings.getString(aButtonKey + "Accesskey")); 
context:   _setUpButton: function (aButtonID, aButtonKey, aDisabled)  {    var strings = document.getElementById("updateStrings");    var button = document.documentElement.getButton(aButtonID);    if (aButtonKey) {      button.label = strings.getString(aButtonKey);      try {        button.accesskey = strings.getString(aButtonKey + "Accesskey");      }      catch (e) {      }    }    button.disabled = aDisabled;  },
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/ffac6c28493d3be1233891fbb26a6256d15ff13d/update.js/clean/toolkit/mozapps/extensions/content/update.js