I'm sorry to hear Ubuntu One isn't working properly for you. The issue
you're facing was likely fixed just a bit ago on the server side. You
should be able to try to restart the client and should be able to
connect. If you've never been able to connect, then you are likely
affected by bug 488413.
** Attachment added:
.home.hermannjosef..cache.ubuntuone.log.oauth.login.log.gz
http://launchpadlibrarian.net/38587999/.home.hermannjosef..cache.ubuntuone.log.oauth.login.log.gz
** Attachment added: Dependencies.txt
http://launchpadlibrarian.net/38588000/Dependencies.txt
** Attachment