In windows, I've got the same problem, and i fixed it just copying the folders C:\ProgramData\ubuntuone and C:\ProgramData\ubuntuone-storageprotocol to C:\Users\[Your-user]\AppData\Local.
In windows, I've got the same problem, and i fixed it just copying the folders C:\ProgramData\ ubuntuone and C:\ProgramData\ ubuntuone- storageprotocol to C:\Users\ [Your-user] \AppData\ Local.