'Install all updates' doesn't always install 'all' updates

The text 'Install all updates' on the update-notifier menu is misleading, since it doesn't install all updates - only those that are not new upstream versions (e.g. kernel updates). Should be rephrased to something like 'Install common updates' or similar, or launch the update manager if additional (root) permissions are required.

To Reproduce:
When there is a kernel update (or new upstream release for another package):
> Click update notifier icon>Install all updates
> A box flashes briefly and disappears with no reason given

What should happen:
> Launch update manager normally if additional permissions are required

Clicking 'Show updates' to launch the update manager, then clicking 'Install Now' does however work as expected.

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: update-notifier 0.134
ProcVersionSignature: Ubuntu 3.8.0-25.37-generic 3.8.13
Uname: Linux 3.8.0-25-generic i686
ApportVersion: 2.9.2-0ubuntu8.1
Architecture: i386
Date: Fri Jul 5 19:41:58 2013
InstallationDate: Installed on 2013-05-27 (39 days ago)
InstallationMedia: Xubuntu 13.04 "Raring Ringtail" - Release i386 (20130423.1)
MarkForUpload: True
SourcePackage: update-notifier
UpgradeStatus: No upgrade log present (probably fresh install)