Description of problem:
Running the sectool with --use-dbus option on F12 rawhide system produces following traceback. On updated F11 system it works as expected using the same version of sectool.

# sectool --version
sectool 0.9.4
# rpm -q sectool
sectool-0.9.4-1.fc11.i586
# rpm -q fedora-release
fedora-release-11.91-3.noarch

# sectool --use-dbus --list
Traceback (most recent call last):
  File "/usr/sbin/sectool", line 418, in run
    bus = DBusCaller()
  File "/usr/sbin/sectool", line 330, in __init__
    self.dbus_action_object = self.bus.get_object ("org.fedoraproject.sectool.mechanism", "/org/fedoraproject/sectool/object")
  File "/usr/lib/python2.6/site-packages/dbus/bus.py", line 244, in get_object
    follow_name_owner_changes=follow_name_owner_changes)
  File "/usr/lib/python2.6/site-packages/dbus/proxies.py", line 241, in __init__
    self._named_service = conn.activate_name_owner(bus_name)
  File "/usr/lib/python2.6/site-packages/dbus/bus.py", line 183, in activate_name_owner
    self.start_service_by_name(bus_name)
  File "/usr/lib/python2.6/site-packages/dbus/bus.py", line 281, in start_service_by_name
    'su', (bus_name, flags)))
  File "/usr/lib/python2.6/site-packages/dbus/connection.py", line 630, in call_blocking
    message, timeout)
DBusException: org.freedesktop.DBus.Error.Spawn.ChildExited: Launch helper exited with unknown return code 1

# rpm -qf /usr/lib/python2.6/site-packages/dbus/bus.py
dbus-python-0.83.0-6.fc12.i686

Current result:
traceback

Expected result:
no traceback and list of tests (in this example)