add:   aEvent.preventDefault(); 
context:   getBrowserTargetFromEvent: function (aEvent)  {    if (!aEvent)      return null;    switch (aEvent.type) {    case "click":    case "dblclick":      if (aEvent.button > 1)        return null;      if (aEvent.button != 1 && !aEvent.metaKey && !aEvent.ctrlKey)        return "current";      break;    case "keypress":    case "command":      if (!aEvent.metaKey && !aEvent.ctrlKey)        return "current";      break;    default:      return null;    }    if (PREF && PREF.getBoolPref("browser.tabs.opentabfor.middleclick"))      return this.shouldLoadTabInBackground(aEvent) ? "tab_background" : "tab";    if (PREF && PREF.getBoolPref("middlemouse.openNewWindow"))      return "window";    return null;  },
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/b83646d0641e9b77373ed407446b9a52e5e8d3ba/bookmarks.js/buggy/xpfe/components/bookmarks/resources/bookmarks.js