Comment 2 for bug 515233

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. Please see that bug description for details on installing an update that fixes the problem.

Thank you,

Joshua