Traceback (most recent call last):
  File "/usr/lib/pymodules/python2.6/papyon/switchboard_manager.py", line 77, in <lambda>
    lambda sb, contact: self.__on_user_left(contact))
  File "/usr/lib/pymodules/python2.6/papyon/switchboard_manager.py", line 140, in __on_user_left
    self.participants.remove(contact)
KeyError: <papyon.Contact id='684c421b-98b4-4627-a98f-1c6fcd3d09ef' network='1' account='lauzziem@hotmail.com' memberships='FORWARD | ALLOW | REVERSE'>