diff -uNr calibre.old/src/calibre/gui2/ui.py calibre/src/calibre/gui2/ui.py

--- calibre.old/src/calibre/gui2/ui.py	2011-12-30 17:12:37.909499254 +0100

+++ calibre/src/calibre/gui2/ui.py	2011-12-30 17:14:33.899450513 +0100

@@ -681,7 +681,8 @@

         if write_settings:

             self.write_settings()

         self.check_messages_timer.stop()

-        self.update_checker.terminate()

+        if hasattr(self, 'update_checker') and self.update_checker:

+            self.update_checker.terminate()

         self.listener.close()

         self.job_manager.server.close()

         self.job_manager.threaded_server.close()

diff -uNr calibre.old/src/calibre/gui2/update.py calibre/src/calibre/gui2/update.py

--- calibre.old/src/calibre/gui2/update.py	2011-12-30 17:12:37.910499245 +0100

+++ calibre/src/calibre/gui2/update.py	2011-12-30 17:14:11.307655638 +0100

@@ -122,11 +122,11 @@

     def __init__(self, opts):

         self.last_newest_calibre_version = NO_CALIBRE_UPDATE

-        if not opts.no_update_check:

-            self.update_checker = CheckForUpdates(self)

-            self.update_checker.update_found.connect(self.update_found,

-                    type=Qt.QueuedConnection)

-            self.update_checker.start()

+        #if not opts.no_update_check:

+        #    self.update_checker = CheckForUpdates(self)

+        #    self.update_checker.update_found.connect(self.update_found,

+        #            type=Qt.QueuedConnection)

+        #    self.update_checker.start()

     def recalc_update_label(self, number_of_plugin_updates):

         self.update_found('%s%s%d'%(self.last_newest_calibre_version, VSEP,