Update Manager frozen...

... for some days. I see on the update-manager icon on gnome-panel it has got 47 updates, but when I load the Update Manager window it always freezes... :(

I've got Debian Squeeze x86 with this sources.list ->

deb http://http.us.debian.org/debian/ squeeze non-free contrib main

deb cdrom:[Debian GNU/Linux 6.0.0 _Squeeze_ - Official Snapshot i386 LIVE/INSTALL Binary 20110324-09:22]/ squeeze main

deb ftp://ftp.kfki.hu/pub/linux/debian/ squeeze main non-free contrib

# deb http://ppa.launchpad.net/ubuntu-x-swat/x-updates/ubuntu lucid main

# deb-src http://ppa.launchpad.net/ubuntu-x-swat/x-updates/ubuntu lucid main

# deb http://www.lamaresh.net/apt squeeze main

# deb http://www.deb-multimedia.org squeeze main non-free

# deb http://www.deb-multimedia.org squeeze-backports main

deb ftp://ftp.kfki.hu/pub/linux/debian/ squeeze-proposed-updates non-free main contrib

deb http://ppa.launchpad.net/webupd8team/java/ubuntu precise main

deb-src http://ppa.launchpad.net/webupd8team/java/ubuntu precise main

deb http://http.debian.net/debian/ squeeze-lts main contrib non-free

deb-src http://http.debian.net/debian/ squeeze-lts main contrib non-free

deb http://http.debian.net/debian/ squeeze main contrib non-free

deb-src http://http.debian.net/debian/ squeeze main contrib non-free

deb http://security.debian.org/ squeeze/updates main non-free contrib

What happened?

Please help repairing my Update Manager!

Thanks and Merry Christmas!