Ubuntu top and bottom panels will not update

[NoBugs!]

Binary package hint: gnome-panel

This has happened on 9.04 and 9.10.
Sometimes the panels stop and won't update, the system-monitor applet won't change, and none of the other icons change when they should. Also, new applications don't show up at the bottom window-list, but they do minimize or show the program when you click where it should be on the bottom panel.

Clicking the icons still works, but the icons never change, not even if panel is hidden and shown again with the hide buttons.

ProblemType: Bug
Architecture: i386
Date: Tue Dec 1 18:48:49 2009
DistroRelease: Ubuntu 9.10
NonfreeKernelModules: wl
Package: gnome-panel 1:2.28.0-0ubuntu6
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-15.50-generic
SourcePackage: gnome-panel
Uname: Linux 2.6.31-15-generic i686

[Sebastien Bacher (seb128)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. Please try to obtain a backtrace following the instructions at http://wiki.ubuntu.com/DebuggingProgramCrash and upload the backtrace (as an attachment) to the bug report. This will greatly help us in tracking down your problem.

[Pedro Villavicencio (pedro)]

We are closing this bug report because it lacks the information we need to investigate the problem, as described in the previous comments. Please reopen it if you can give us the missing information, and don't hesitate to submit bug reports in the future. To reopen the bug report you can click on the current status, under the Status column, and change the Status back to New. Thanks again!.

[NoBugs! (luke32j)]

This still happens occasionally (at least with the top bar), even with up-to-date system.
The end of the bug-reporting tool's output gave:
----------- .xsession-errors (140 sec old) ---------------------
** (gnome-panel:2801): DEBUG: Adding applet 27.
Unable to open desktop file /home/(rhythmbox.desktop file) for panel launcher: No such file or directory
Unable to open desktop file /home/(Another file that doesn't exist) for panel launcher: No such file or directory
Unable to open desktop file main.xml?ignore.mscache=3977188
.desktop for panel launcher
** (rhythmbox:14384): CRITICAL **: atk_object_set_name: assertion `name != NULL' failed
** (rhythmbox:14384): CRITICAL **: atk_object_set_name: assertion `name != NULL' failed
** (rhythmbox:14384): CRITICAL **: atk_object_set_name: assertion `name != NULL' failed
/usr/lib/pymodules/python2.6/rpdb2.py:308: DeprecationWarning: the sets module is deprecated
  import sets
/usr/lib/pymodules/python2.6/rpdb2.py:313: DeprecationWarning: The popen2 module is deprecated. Use the subprocess module.
  import popen2
--------------------------------------------------
I had tried to move the rhythmbox icon, it moved but it still shows up only at the old location, everything works fine, but it won't update the screen.

[NoBugs! (luke32j)]

I noticed this seemed to always happen when connecting the second screen to computer, setting it up as 2 screens, then switching back to only the main screen.

I found the following bad entry in ~/.gconf/apps/panel/objects/object_9/%gconf.xml:
<entry name="launcher_location" mtime="1260661334" schema="/schemas/apps/panel/objects/launcher_location" type="string">
  <stringvalue>main.xml?ignore.mscache=3977188
.desktop</stringvalue>
 </entry>

It looks like this was causing it to stop refreshing. I don't know how this entry got there, maybe from dragging-dropping something on the panel somewhere. When I delete this <entry ... </entry> from the file and save it, this strange bug doesn't happen anymore :)

[NoBugs! (luke32j)]

Top panel sometimes does this still...

----------- .xsession-errors (195 sec old) ---------------------
** (nm-applet:2903): DEBUG: going for offline with icon: notification-network-wireless-disconnected
** (nm-applet:2903): DEBUG: going for offline with icon: notification-network-wireless-disconnected
** (nm-applet:2903): DEBUG: foo_client_state_changed_cb
** (nm-applet:2903): DEBUG: going for offline with icon: notification-network-disconnected
** (nm-applet:2903): DEBUG: foo_client_state_changed_cb
** (nm-applet:2903): DEBUG: going for offline with icon: notification-network-disconnected
(gnome-display-properties:16184): Gtk-WARNING **: Ignoring the separator setting
(gnome-display-properties:16184): Gtk-WARNING **: No object called:
** (nm-applet:2903): DEBUG: foo_client_state_changed_cb
(gnome-display-properties:17205): Gtk-WARNING **: Ignoring the separator setting
(gnome-display-properties:17205): Gtk-WARNING **: No object called:
--------------------------------------------------