"Security Updates are Available" notice will not go away

[qajaq]

I've run
$ apt-get update followed by
$ apt-get upgrade. . . but when I re-boot I still get the pop-up telling me that "Security Updates are Available."

I looked at the Muon Package Manager, filtering for installed software, and all items show "No Change."

I'm running Kubuntu 12.04, and this problem has persisted since I installed the OS, a little over a year ago. Any ideas why this pop-up keeps hanging around?

[Old_Grey_Wolf]

sudo apt-get upgrade does not install all security updates; such as, kernel upgrades.

Have you tried
sudo apt-get update && sudo apt-get dist-upgrade

Edit: if it has been a year since you did a kernel upgrade, I would recommend a backup of important files before you do it.

[qajaq]

That did it -- Thank you! (And yes, my files are backed-up daily.)