RuntimeError: To make asynchronous calls, receive signals or export objects, D-Bus connections must be attached to a main loop by passing mainloop=... to the constructor or calling dbus.set_default_main_loop(...)

Traceback (most recent call last):
  File "/usr/lib/rhythmbox/plugins/ubuntuone/ubuntuone.py", line 89, in do_activate
    signal_name='DownloadFinished')
  File "/usr/lib/python2.7/dist-packages/dbus/bus.py", line 148, in add_signal_receiver
    path, **keywords)
  File "/usr/lib/python2.7/dist-packages/dbus/connection.py", line 400, in add_signal_receiver
    self._require_main_loop()
RuntimeError: To make asynchronous calls, receive signals or export objects, D-Bus connections must be attached to a main loop by passing mainloop=... to the constructor or calling dbus.set_default_main_loop(...)

This happens when running Rhythmbox with the latest rhythmbox-ubuntuone installed.