Comment 3 for bug 1038069

non gui option

edit file /etc/apt/apt.conf.d/50unattended-upgrades

uncomment row

 "${distro_id} ${distro_codename}-updates";

see (german) http://wiki.ubuntuusers.de/Aktualisierungen/Konfiguration?redirect=no

But an option in the update-manager would be great.