diff -up hplip-3.10.9/ui4/systemtray.py.notification-exception hplip-3.10.9/ui4/systemtray.py

--- hplip-3.10.9/ui4/systemtray.py.notification-exception	2011-01-05 10:45:57.000000000 +0100

+++ hplip-3.10.9/ui4/systemtray.py	2011-01-05 12:34:18.000000000 +0100

@@ -27,6 +27,7 @@ import os

 import signal

 import os.path

 import time

+import gobject

 # Local

@@ -662,7 +663,10 @@ class SystemTrayApp(QApplication):

                                     else:

                                         n.set_timeout(TRAY_MESSAGE_DELAY)

-                                    n.show()

+                                    try:

+                                        n.show()

+                                    except gobject.GError:

+                                        log.error("Failed to show notification!")

                                 else: # Use "standard" message bubbles

                                     icon = ERROR_STATE_TO_ICON.get(error_state, QSystemTrayIcon.Information)