Salut,
Merci de ton intéret pour mon problème !
Voici ce que donne l’apt-cache policy
13:09 ben@ben-t60 ~% sudo apt-cache policy
Fichiers du paquet :
100 /var/lib/dpkg/status
release a=now
99 http://www.debian-multimedia.org experimental/main Packages
release o=Unofficial Multimedia Packages,a=experimental,l=Unofficial Multimedia Packages,c=main
origin www.debian-multimedia.org
98 http://ftp.fr.debian.org experimental/non-free Packages
release o=Debian,a=experimental,l=Debian,c=non-free
origin ftp.fr.debian.org
98 http://ftp.fr.debian.org experimental/contrib Packages
release o=Debian,a=experimental,l=Debian,c=contrib
origin ftp.fr.debian.org
98 http://ftp.fr.debian.org experimental/main Packages
release o=Debian,a=experimental,l=Debian,c=main
origin ftp.fr.debian.org
998 http://www.debian-multimedia.org sid/main Packages
release o=Unofficial Multimedia Packages,a=unstable,l=Unofficial Multimedia Packages,c=main
origin www.debian-multimedia.org
997 http://ftp.fr.debian.org sid/non-free Packages
release o=Debian,a=unstable,l=Debian,c=non-free
origin ftp.fr.debian.org
997 http://ftp.fr.debian.org sid/contrib Packages
release o=Debian,a=unstable,l=Debian,c=contrib
origin ftp.fr.debian.org
997 http://ftp.fr.debian.org sid/main Packages
release o=Debian,a=unstable,l=Debian,c=main
origin ftp.fr.debian.org
992 http://security.debian.org lenny/updates/non-free Packages
release v=None,o=Debian,a=testing,l=Debian-Security,c=non-free
origin security.debian.org
992 http://security.debian.org lenny/updates/contrib Packages
release v=None,o=Debian,a=testing,l=Debian-Security,c=contrib
origin security.debian.org
992 http://security.debian.org lenny/updates/main Packages
release v=None,o=Debian,a=testing,l=Debian-Security,c=main
origin security.debian.org
991 http://www.debian-multimedia.org lenny/main Packages
release o=Unofficial Multimedia Packages,a=testing,l=Unofficial Multimedia Packages,c=main
origin www.debian-multimedia.org
990 http://ftp.fr.debian.org lenny/non-free Packages
release o=Debian,a=testing,l=Debian,c=non-free
origin ftp.fr.debian.org
990 http://ftp.fr.debian.org lenny/contrib Packages
release o=Debian,a=testing,l=Debian,c=contrib
origin ftp.fr.debian.org
990 http://ftp.fr.debian.org lenny/main Packages
release o=Debian,a=testing,l=Debian,c=main
origin ftp.fr.debian.org
996 http://ftp.ens-cachan.fr etch/volatile/non-free Packages
release o=volatile.debian.org,a=stable,l=debian-volatile,c=non-free
origin ftp.ens-cachan.fr
996 http://ftp.ens-cachan.fr etch/volatile/contrib Packages
release o=volatile.debian.org,a=stable,l=debian-volatile,c=contrib
origin ftp.ens-cachan.fr
996 http://ftp.ens-cachan.fr etch/volatile/main Packages
release o=volatile.debian.org,a=stable,l=debian-volatile,c=main
origin ftp.ens-cachan.fr
995 http://security.debian.org etch/updates/non-free Packages
release v=4.0,o=Debian,a=stable,l=Debian-Security,c=non-free
origin security.debian.org
995 http://security.debian.org etch/updates/contrib Packages
release v=4.0,o=Debian,a=stable,l=Debian-Security,c=contrib
origin security.debian.org
995 http://security.debian.org etch/updates/main Packages
release v=4.0,o=Debian,a=stable,l=Debian-Security,c=main
origin security.debian.org
994 http://www.debian-multimedia.org etch/main Packages
release o=Unofficial Multimedia Packages,a=stable,l=Unofficial Multimedia Packages,c=main
origin www.debian-multimedia.org
993 http://ftp.fr.debian.org etch/non-free Packages
release v=4.0r3,o=Debian,a=stable,l=Debian,c=non-free
origin ftp.fr.debian.org
993 http://ftp.fr.debian.org etch/contrib Packages
release v=4.0r3,o=Debian,a=stable,l=Debian,c=contrib
origin ftp.fr.debian.org
993 http://ftp.fr.debian.org etch/main Packages
release v=4.0r3,o=Debian,a=stable,l=Debian,c=main
origin ftp.fr.debian.org
Paquets étiquetés :
Et voici ce que donne le sources.list
[code]13:09 ben@ben-t60 ~% cat /etc/apt/sources.list
etch
deb http://ftp.fr.debian.org/debian/ etch main contrib non-free
deb-src http://ftp.fr.debian.org/debian/ etch main contrib non-free
#debian-marillat
deb http://www.debian-multimedia.org etch main
deb-src http://www.debian-multimedia.org etch main
security
deb http://security.debian.org/ etch/updates main contrib non-free
deb-src http://security.debian.org/ etch/updates main contrib non-free
volatile
deb http://ftp.ens-cachan.fr/ftp/debian-volatile etch/volatile main contrib non-free
deb-src http://ftp.ens-cachan.fr/ftp/debian-volatile etch/volatile main contrib non-free
lenny
deb http://ftp.fr.debian.org/debian/ lenny main contrib non-free
deb-src http://ftp.fr.debian.org/debian/ lenny main contrib non-free
#debian-marillat
deb http://www.debian-multimedia.org lenny main
deb-src http://www.debian-multimedia.org lenny main
security
deb http://security.debian.org/ lenny/updates main contrib non-free
deb-src http://security.debian.org/ lenny/updates main contrib non-free
sid
deb http://ftp.fr.debian.org/debian/ sid main contrib non-free
deb-src http://ftp.fr.debian.org/debian/ sid main contrib non-free
#debian-marillat
deb http://www.debian-multimedia.org sid main
deb-src http://www.debian-multimedia.org sid main
experimental
deb http://ftp.fr.debian.org/debian/ experimental main contrib non-free
deb-src http://ftp.fr.debian.org/debian/ experimental main contrib non-free
#debian-marillat
deb http://www.debian-multimedia.org experimental main
deb-src http://www.debian-multimedia.org experimental main
[/code]
J’avoue ne pas avoir encore tout compris aux Etch, Sid, Unstable.
Les fichiers sont issus de ce forum 
Je donne un cours Cisco CCNA ce soir avec OpenOffice, qui est mourru pour le moment !
Merci,
Ben