Non riesco ad installare Nautilus

[<omar.crea@thyme.it>]

Ciao a tutti. 
Da ieri, dopo aver aggiornato il sistema 
(apt-get update && apt-get dist-upgrade) non riesco piu' a navigare 
le directory del mio file system. Se provo ad aprirne una, ad 
esempio la mia home, ottengo una dialog col seguente messaggio:
"Could not open location file"
"There is no default action associated with this location"

Adesso nel mio sistema il pacchetto nautilus e' nel seguente stato: 
$ dpkg -l nautilus
Desired=Unknown/Install/Remove/Purge/Hold
|
Status=Not/Inst/Cfg-files/Unpacked/Failed-cfg/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Hold/Reinst-required/X=both-problems (Status,Err:
uppercase=bad)
||/ Name            Version        Description
+++-=========-=================================================================
rc  nautilus        2.20.0-7       file manager and graphical shell for
GNOME

Se provo a reinstallarlo ottengo il seguente errore:
apt-get install nautilus
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
  nautilus: Depends: libeel2-2.20 but it is not going to be installed
            Depends: libgnome-desktop-2 (>= 2.22.0) but it is not going to
be installed
            Depends: libgnome2-0 (>= 2.17.3) but it is not going to be
installed
            Depends: libgnomeui-0 (>= 2.17.1) but it is not going to be
installed
            Depends: libgnomevfs2-0 (>= 1:2.17.90) but it is not going to
be installed
            Depends: shared-mime-info but it is not going to be installed
            Depends: gnome-control-center (>= 2.6) but it is not going to
be installed
            Recommends: nautilus-cd-burner (>= 2.6) but it is not going to
be installed
            Recommends: libgnomevfs2-extra but it is not going to be
installed
E: Broken packages

Il comando "apt-get -f install" da' il seguente output:
apt-get -f install
Reading package lists... Done
Building dependency tree       
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

Il problema si e' verificato dopo il passaggio di lenny come versione
stabile, 
perche' avevo alcune risorse nel sources.list che puntavano a lenny invece
che 
a testing (la distro che voglio usare). Comunque avevo corretto e
rilanciato 
update, ma il risultato e' lo stesso.