Toggling the checkbox for a *group* of updates incorrectly toggles the individual updates

[Matthew Pirocchi]

Steps to reproduce:

1. Start update-manager when one of your software sources (say, a PPA) has multiple updates available.
2. Manually un-check each individual update from the source.
3. Un-check the checkbox for the source itself.
4. Re-check the checkbox for the source itself.

Expected results:
- After step 3, all the individual updates remain un-checked.
- After step 4, all the individual updates are checked.

Actual results:
Toggling the group's checkbox simply toggles the checkboxes for the indivudual sources. So:

- After step 3, all the individual updates become checked.
- After step 4, all the individual updates become un-checked.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: update-manager 1:0.156.14.5
ProcVersionSignature: Ubuntu 3.2.0-26.41-generic 3.2.19
Uname: Linux 3.2.0-26-generic x86_64
ApportVersion: 2.0.1-0ubuntu8
Architecture: amd64
Date: Tue Jul 17 10:56:29 2012
GsettingsChanges:
 com.ubuntu.update-manager first-run false
 com.ubuntu.update-manager launch-time 1342536878
 com.ubuntu.update-manager show-details true
 com.ubuntu.update-manager window-height 859
 com.ubuntu.update-manager window-width 600
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
PackageArchitecture: all
SourcePackage: update-manager
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Robert Roth (evfool)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug #1039543, so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Feel free to continue to report any other bugs you may find.