Comment 1 for bug 414181

@mvo, this should probably be SRU'd into karmic?

I can confirm this on two separate machines, one is a clean karmic install and one is an upgraded machine. For me, it only happens if you let update-manager open by itself (the way it does after two weeks or whatever). When I explicitly click System::Administration::UpdateManager the install button works as expected.

I believe that when update manager is launched implicitly (i.e. when it automatic opens at startup if not used for two weeks when there is updates available) then the code inside the "install" button that handles privilege escalation fails somehow. It fails to even get to the point where the root password prompt is engaged.

I find nothing in dmesg after this happened but there is an interesting error message printed into ~/.xsession-errors:

** (update-notifier:1691): DEBUG: --security-updates-unattended: 0
Window manager warning: Buggy client sent a _NET_ACTIVE_WINDOW message with a timestamp of 0 for 0x4200027 (Update Man)
Window manager warning: meta_window_activate called by a pager with a 0 timestamp; the pager needs to be fixed.
Traceback (most recent call last):
  File "/usr/lib/python2.6/dist-packages/UpdateManager/UpdateManager.py", line 581, in on_button_install_clicked
    self.cache.checkFreeSpace()
  File "/usr/lib/python2.6/dist-packages/DistUpgrade/DistUpgradeCache.py", line 1051, in checkFreeSpace
    for (dir, size) in [(archivedir, self.requiredDownload),
  File "/usr/lib/python2.6/dist-packages/UpdateManager/Core/MyCache.py", line 72, in requiredDownload
    pm.GetArchives(fetcher, self._list, self._records)