The gnome metacity fallback doesn't update the background producing a Windows XP-esque effect:
I first thought this was a problem with my gnome configuration. I deleted my config and cleaned up my .* config files. But the result was the same. I'm kind of at a loss here on how to debug this.
Installed packages: http://pastebin.com/raw.php?i=nkY7Kieg
The relevant puppet configuration to reproduce the bug is located here: http://pastebin.com/raw.php?i=w2pshfUV
The problem doesn't occur with the compiz fallback (however there individual workspaces don't work). Interestingly it doesn't show any background as well.
Since there's no background available I guess that I forgot something to start (or something can't start).
So what does Gnome use for backgrounds these days? Is it still Nautilus?
I think part of the problem is that I started with the Ubuntu installer and then added all the Installers on top of it. I think the OS is missing some dependencies. But I'm not sure on how to debug these.
I deleted the following config folders:
rm -rf .gnome .gnome2 .gconf .gconfd .metacity .cache .dbus .dmrc .mission-control .thumbnails .config .Xauthority .gvfs .gegl-0.0 .local .pulse-cookie .fontconfig
Edit: Manually executing
nautilus --force-desktop seems to work around the issue.