--- a/browser/components/preferences/applications.js
+++ b/browser/components/preferences/applications.js
@@ -533,18 +533,17 @@ FeedHandlerInfo.prototype = {
   // Convenience Utils
 
   _converterSvc:
     Cc["@mozilla.org/embeddor.implemented/web-content-handler-registrar;1"].
     getService(Ci.nsIWebContentConverterService),
 
   _shellSvc:
 #ifdef HAVE_SHELL_SERVICE
-    Cc["@mozilla.org/browser/shell-service;1"].
-    getService(Ci.nsIShellService),
+    getShellService(),
 #else
     null,
 #endif
 
 
   //**************************************************************************//
   // nsIHandlerInfo
 
@@ -665,17 +664,17 @@ FeedHandlerInfo.prototype = {
       return this.__defaultApplicationHandler;
 
     var defaultFeedReader = null;
 #ifdef HAVE_SHELL_SERVICE
     try {
       defaultFeedReader = this._shellSvc.defaultFeedReader;
     }
     catch(ex) {
-      // no default reader
+      // no default reader or _shellSvc is null
     }
 #endif
 
     if (defaultFeedReader) {
       let handlerApp = Cc["@mozilla.org/uriloader/local-handler-app;1"].
                        createInstance(Ci.nsIHandlerApp);
       handlerApp.name = getDisplayNameForFile(defaultFeedReader);
       handlerApp.QueryInterface(Ci.nsILocalHandlerApp);
@@ -692,17 +691,17 @@ FeedHandlerInfo.prototype = {
 
   get hasDefaultHandler() {
 #ifdef HAVE_SHELL_SERVICE
     try {
       if (this._shellSvc.defaultFeedReader)
         return true;
     }
     catch(ex) {
-      // no default reader
+      // no default reader or _shellSvc is null
     }
 #endif
 
     return false;
   },
 
   get defaultDescription() {
     if (this.hasDefaultHandler)