ImportError: No module named gconf

[dino99]

Does not know about which package to report exactly: get these lines logged at the very beginning of xsession-errors

org.gtk.vfs.MountTracker.listMountableInfo call failed: GDBus.Error:org.freedesktop.DBus.Error.UnknownMethod: L'interface « org.gtk.vfs.MountTracker » n'existe pas pour l'objet à l'emplacement /org/gtk/vfs/mounttracker (g-dbus-error-quark, 19)
Exited with an error
stdout:
stderr: Traceback (most recent call last):
  File "/usr/share/session-migration/scripts/02_migrate_to_gsettings.py", line 22, in <module>
    import gconf
ImportError: No module named gconf

ProblemType: Bug
DistroRelease: Ubuntu 12.10
Package: gnome-session 3.5.5-0ubuntu3
Uname: Linux 3.6.0-030600rc3-generic i686
ApportVersion: 2.5.1-0ubuntu2
Architecture: i386
Date: Sat Aug 25 10:04:38 2012
PackageArchitecture: all
SourcePackage: gnome-session
UpgradeStatus: No upgrade log present (probably fresh install)