DFF application return a error on button "Open local device"

[virtualmind]

When i try to open a local device as a hard disk ide the error window say:

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/dff/ui/gui/dialog/dialog.py", line 65, in addDevices
    dev = DevicesDialog(self.parent)
  File "/usr/lib/python2.7/dist-packages/dff/api/gui/widget/devicesdialog.py", line 38, in __init__
    self.devices = Devices()
  File "/usr/lib/python2.7/dist-packages/dff/api/devices/devices.py", line 33, in __init__
    self.__instance = DBusHalDevices()
  File "/usr/lib/python2.7/dist-packages/dff/api/devices/dbushaldev.py", line 105, in __init__
    proxy = system_bus.get_object(bus_name, object)
  File "/usr/lib/python2.7/dist-packages/dbus/bus.py", line 241, in get_object
    follow_name_owner_changes=follow_name_owner_changes)
  File "/usr/lib/python2.7/dist-packages/dbus/proxies.py", line 248, in __init__
    self._named_service = conn.activate_name_owner(bus_name)
  File "/usr/lib/python2.7/dist-packages/dbus/bus.py", line 180, in activate_name_owner
    self.start_service_by_name(bus_name)
  File "/usr/lib/python2.7/dist-packages/dbus/bus.py", line 278, in start_service_by_name
    'su', (bus_name, flags)))
  File "/usr/lib/python2.7/dist-packages/dbus/connection.py", line 651, in call_blocking
    message, timeout)
dbus.exceptions.DBusException: org.freedesktop.DBus.Error.Spawn.ChildExited: Launch helper exited with unknown return code 1

i have open dff -g as root too

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: dff 1.2.0+dfsg.1-1
ProcVersionSignature: Ubuntu 3.8.0-23.34-generic 3.8.11
Uname: Linux 3.8.0-23-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.9.2-0ubuntu8.1
Architecture: amd64
Date: Fri Jun 7 07:56:54 2013
EcryptfsInUse: Yes
InstallationDate: Installed on 2012-11-18 (200 days ago)
InstallationMedia: Ubuntu 12.04.1 LTS "Precise Pangolin" - Release amd64 (20120817.1)
MarkForUpload: True
SourcePackage: dff
UpgradeStatus: Upgraded to raring on 2013-06-01 (5 days ago)

[Launchpad Janitor (janitor)]

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