такая же проблема, поначалу запускалось, теперь перестало...
motors@motors:~$ indicator-datetime-preferences
(indicator-datetime-preferences:2117): Unique-DBus-WARNING **: Error while sending message: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.