Bug#569035: deleting old config file solves problem

[Andrew Engelbrecht]

I tried removing /etc/dbus-1/system.d/system-tools-backends.conf, and
found that it solves the problem. Doing this lets an admin launch the
*-admin programs, and authenticate to make any changes, as normal.
This way, you don't have to manually add yourself and every new admin
account to the stb-admin group.

Running the following command deletes the config file:

sudo apt-get --reinstall install --purge system-tools-backends

the purge option deletes any files that aren't listed in the current
package (i.e. files left over from lenny.) alternatively, you can just
rm it, but it will still be listed in the database used by dpkg.

I guess the solution for the maintainer is to delete the file upon upgrade. : )