network manager cannot authenticate

Confirmed.

I have not seen this on Ubuntu, but it is happening on a very minimal Xubuntu that I have.

When I click on the Unlock button in Network Manager, I get the same dialog reported above.

   Could not authenticate
   An unexpected error has occurred.

When running network-admin from the command line, the following error is reported:
   ** (network-admin:22011): CRITICAL: **: The name org.gnome.PolicyKit was not provided by any
   .service files.

Seems that it needs the file:
   /usr/share/dbus-1/services/org.gnome.PolicyKit.service

Is provided by:
   policykit-gnome

Which is missing from this system. Installing it solves the problem. Looks like a dependency bug.

It seems that the binary:
   /usr/bin/network-admin

Is owned by:
   gnome-system-tools

I will be submitting a debdiff shortly that adds policykit-gnome to the Requires for gnome-system-tools

Other administrative dialogs work fine, such as Hardware Drivers.

This is actually seems to be a bug in the dependency list in the gnome-system-tools package, as network-admin is the underlying binary that I called to reproduce this problem.

Invalid, not a network-manager bug, per se, but it might seem to be, to some users. Leaving here for searchability.

Attached debdiff adds the explicit dependency on policykit-gnome.

Per discussion in IRC with seb128, policykit-gnome should be moved from Depends Recommends. Additionally, gksu should be removed from Recommends.

Debdiff attached.

Sébastien: can you take a look at it?

Thank you for your work, new revision uploaded

This bug was fixed in the package gnome-system-tools - 2.22.0-0ubuntu6

---------------
gnome-system-tools (2.22.0-0ubuntu6) hardy; urgency=low

  * debian/control, debian/control.in: remove gksu from Recommends, add
    policykit-gnome; needed to press the Unlock button in network-admin,
    LP: #206198

 -- Dustin Kirkland <email address hidden> Thu, 03 Apr 2008 09:18:03 -0500