gnome-panel has multiple rows -- how to undo that?

On Ubuntu 12.04 I use openbox with a single "gnome-panel" started. But after trying to configure my two screen in Xinerama mode I got additional rows of panels each time X restarted.

And despite I completely reverted to my one-screen-X-config

• the gnome-panel displayed has 4 rows (4 at top sreen, 4 at bottom)
• only the outermost row has content, the other 3 are empty
• there is only one gnome-panel process running
• some widgets appear 4 times, too, although they run only once
• when I switch away from openbox using unity I am back to 1 row temporarily

What went wrong here? How do I undo that? Things that did not help:

• rm -Rf .gnome2 .gconf/ .compiz-1/
• pkill panel, and restarting it

Solution 1:

Run the following, apparently gnome3 stores configuration in binary form (I haven't read up on dconf enough to know where or why).

sudo apt-get install dconf-tools

Run: dconf-editor to edit the config.

Go to: org.gnome.gnome-panel.layout (it's pretty intuitive)

The defaults seem to be:

object-id-list     ['menu-bar', 'indicators', 'show-desktop', 'window-list', 'workspace-switcher']
toplevel-id-list   ['top-panel', 'bottom-panel']

I had to figure this out after I had some weird issue with gnome while trying to get my 2 monitors to work. Everything (menus, rows, clock, etc.) seemed to duplicate on the panel after every attempt to restart the X server. I should have took a screenshot but this is essentially what I had before I fixed it:

object-id-list     ['menu-bar', 'indicators', 'show-desktop', 'window-list', 'workspace-switcher', 'menu-bar-0', 'indicators-0', 'show-desktop-0', 'window-list-0', 'workspace-switcher-0', 'menu-bar-1', 'indicators-1', 'show-desktop-1', 'window-list-1', 'workspace-switcher-1']
toplevel-id-list   ['top-panel', 'bottom-panel', 'top-panel-screen1', 'bottom-panel-screen1', 'top-panel-screen1-0', 'bottom-panel-screen1-0']

As you can see, there's 3 of everything.

Solution 2:

Thanks to zechariah.

What about:

dconf reset -f /org/gnome/gnome-panel/layout/

That got rid of 3 of my four panels.