Gmail plugin does not save the login credentials

[schorsch]

When entering the login credentials for the gmail plugin I get the following exception:

Traceback (most recent call last):
  File "/home/stefan/coding/general/kupfer/kupfer/ui/preferences.py", line 597, in callback
    setctl.set_plugin_config(plugin_id, key, upass, val_type)
  File "/home/stefan/coding/general/kupfer/kupfer/core/settings.py", line 355, in set_plugin_config
    value_repr = value.save(plugin, key)
  File "/home/stefan/coding/general/kupfer/kupfer/plugin_support.py", line 186, in save
    keyring.set_password(plugin_id, str(self.username), self.password)
  File "/usr/lib/python2.7/dist-packages/keyring/core.py", line 42, in set_password
    _keyring_backend.set_password(service_name, username, password)
  File "/usr/lib/python2.7/dist-packages/keyring/backend.py", line 234, in set_password
    True)
  File "/usr/lib/python2.7/dist-packages/dbus/proxies.py", line 70, in __call__
    return self._proxy_method(*args, **keywords)
  File "/usr/lib/python2.7/dist-packages/dbus/proxies.py", line 145, in __call__
    **keywords)
  File "/usr/lib/python2.7/dist-packages/dbus/connection.py", line 641, in call_blocking
    message.append(signature=signature, *args)
TypeError: Expected a string or unicode object

Do I have to make sure that some kind of deamon is running?

Current Kupfer version: 04bbd63c
Ubuntu 12.04