add:  var newMailNotificationTrayIconPref = document.getElementById("newMailNotificationTrayIcon"); newMailNotificationTrayIconPref.hidden = !/^Win/.test(navigator.platform); 
context: function Startup(){  PlaySoundCheck();  // if we don't have the alert service, hide the pref UI for using alerts to notify on new mail  // see bug #158711  var newMailNotificationAlertUI = document.getElementById("newMailNotificationAlert");  newMailNotificationAlertUI.hidden = !("@mozilla.org/alerts-service;1" in Components.classes);  if (!/Mac/.test(navigator.platform))    document.getElementById('newMailNotificationBounce').setAttribute("hidden", true);}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/a1c4cf08fc26e1a7e857507048758c66cd0f3b0c/pref-notifications.js/buggy/mailnews/base/prefs/resources/content/pref-notifications.js