Comment 4 for bug 976761

Aha, thanks. Took me a little bit to wrap my brain around this, but yes, I see the bug now; the 'Run this command' needs to run as root, and curently it's being run as the admin user. Will get this fixed.

To work around this problem, you can run 'sudo /usr/lib/update-notifier/package-data-downloader' from a terminal.