diff -burN calibre-2.9.0.orig/src/calibre/gui2/main.py calibre-2.9.0/src/calibre/gui2/main.py
--- calibre-2.9.0.orig/src/calibre/gui2/main.py	2014-11-09 20:09:54.081231882 +0800
+++ calibre-2.9.0/src/calibre/gui2/main.py	2014-11-09 20:15:48.193033844 +0800
@@ -37,8 +37,9 @@
                       help=_('Start minimized to system tray.'))
     parser.add_option('-v', '--verbose', default=0, action='count',
                       help=_('Ignored, do not use. Present only for legacy reasons'))
-    parser.add_option('--no-update-check', default=False, action='store_true',
-            help=_('Do not check for updates'))
+    parser.add_option('--update-check', dest='no_update_check', default=True,
+            action='store_false',
+            help=_('Check for updates'))
     parser.add_option('--ignore-plugins', default=False, action='store_true',
             help=_('Ignore custom plugins, useful if you installed a plugin'
                 ' that is preventing calibre from starting'))
diff -burN calibre-2.9.0.orig/src/calibre/gui2/update.py calibre-2.9.0/src/calibre/gui2/update.py
--- calibre-2.9.0.orig/src/calibre/gui2/update.py	2014-11-09 20:09:54.082231864 +0800
+++ calibre-2.9.0/src/calibre/gui2/update.py	2014-11-09 20:17:49.954767115 +0800
@@ -154,6 +154,8 @@
             self.update_checker.signal.update_found.connect(self.update_found,
                     type=Qt.QueuedConnection)
             self.update_checker.start()
+        else:
+            self.update_checker = None
 
     def recalc_update_label(self, number_of_plugin_updates):
         self.update_found(self.last_newest_calibre_version, number_of_plugin_updates)