Comment 71 for bug 356152

I just reinstalled 'update-manager-common' and 'update-manager' and executed:

/usr/lib/update-notifier/update-motd-updates-available --force
  16 Softwarepakete können aktualisiert werden.
  0 Aktualisierungen sind Sicherheitsaktualisierungen.

This information is also logged in
               /var/lib/update-notifier/updates-available

Translation:
16 upgradable packages, 0 of them are security updates.
Remark:
the 2 security packages for SSH I did install manually meanwhile for obvious reasons

But still I do not receive any notification

Unfortunately I don't have any more idea how to further dig into that problem, which logs to search for what, ... please help.