TypeError: More items found in D-Bus signature than in Python arguments

[Federico]

Hi all
Don't know if this error is more related to Dbus or to Hal.
In a Python application, while trying to unmount a device through Hal,
I get this:

ERROR:dbus.connection:Unable to set arguments () according to
signature u'as': <type 'exceptions.TypeError'>: More items found in
D-Bus signature than in Python arguments
Traceback (most recent call last):
  File "/home/fredp/Progetti/ejecter/newui.py", line 110, in _clicked_eject
    shared.eject(self.udi)
  File "./ejecter.py", line 123, in eject_device
    dev.Eject()
  File "/var/lib/python-support/python2.5/dbus/proxies.py", line 68, in __call__
    return self._proxy_method(*args, **keywords)
  File "/var/lib/python-support/python2.5/dbus/proxies.py", line 140,
in __call__
    **keywords)
  File "/var/lib/python-support/python2.5/dbus/connection.py", line
597, in call_blocking
    message.append(signature=signature, *args)
TypeError: More items found in D-Bus signature than in Python arguments


This is the code that produces that error:

obj = self.bus.get_object("org.freedesktop.Hal", udi)
dev = dbus.Interface(obj, 'org.freedesktop.Hal.Device.Volume')
dev.Eject()

What causes this? How can I solve?

If necessary you find the whole sources here:
http://bazaar.launchpad.net/~fredp/ejecter/main/files

Thank you