I have the same problem, I need to do an apt-get update manually to have a message from update-notifier.
$ ls -l /var/lib/apt/periodic/ total 0 -rw-r--r-- 1 root root 0 2006-06-15 07:35 update-stamp -- update notifier does not work automagically https://launchpad.net/bugs/43995 -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
