[MEGOLDVA] Backports hasznalata

Udv!

Elég alap kérdéssel fordulok hozzátok. Elolvasva a wiki-t https://wiki.debian.org/Backports

Elvileg egyszerű lenne új libreoffice-t és iceweasel-t használni, de nekem nem jön össze:

sudo aptitude -t wheezy-backports install iceweasel
No packages will be installed, upgraded, or removed.
0 packages upgraded, 0 newly installed, 0 to remove and 70 not upgraded.
Need to get 0 B of archives. After unpacking 0 B will be used.

Pedig a source.list-ben:

deb http://ftp.debian.org/debian wheezy-backports main contrib non-free
deb-src http://ftp.debian.org/debian wheezy-backports main contrib non-free

És:

apt-cache policy iceweasel
iceweasel:
Installed: 20.0-1
Candidate: 20.0-1
Version table:
26.0-1~bpo70+1 0
500 http://mozilla.debian.net/ wheezy-backports/iceweasel-release i386 Packages
*** 20.0-1 0
1001 http://packages.crunchbang.org/waldorf/ waldorf/main i386 Packages
100 /var/lib/dpkg/status
17.0.10esr-1~deb7u1 0
500 http://http.debian.net/debian/ wheezy/main i386 Packages
500 http://security.debian.org/ wheezy/updates/main i386 Packages

Vajon mit hagytam ki? Crunchbang-et használok.
Köszönöm a segítséget.

Szerk:
/etc/apt/preferences:

Package: *
Pin: release a=waldorf
Pin-Priority: 1001

Package: *
Pin: release a=wheezy
Pin-Priority: 500

Package: *
Pin: release a=wheezy-backports
Pin-Priority: 2000

Szerk 2:
Megoldás:
/etc/apt/preferences:

Package: *
Pin: release a=waldorf
Pin-Priority: 900

Package: *
Pin: release a=wheezy
Pin-Priority: 500

Package: *
Pin: release a=wheezy-backports
Pin-Priority: 999