The Ubuntu One client for Windows doesn't really bring us much closer to a client for the Windows Phone platform. Our desktop client is written in Python (and shares most of its code with the Ubuntu version), while WP7 apps need to be written with XNA or Silverlight.

Also, the desktop client works in terms of synchronising all of your files locally, while on a mobile platform where storage is limited and bandwidth constrained, it is more useful to be able to browse all of your files and only download the ones you're interested in (which is how the Android files app works).

While we don't have immediate plans to release a WP7 native application, the API that the Android client uses to access the service is publicly documented if you're interested in developing an application yourself:

https://one.ubuntu.com/developer/files/store_files/cloud

You also have the option to use Ubuntu One's web interface to access your files.

Firstly, sorry to hear you're having problems. It would be worth contacting the U1 support team who are excellent because they may be able to help. However, there are other ways to access Ubuntu One. The U1 website is one of those ways: you can upload and download your files there. You may also find u1ftp (tutorial and instructions at http://www.kryogenix.org/days/2012/09/11/accessing-ubuntu-one-file-storage-via-ftp-from-any-os) an interesting approach if you're happy to access your data directly in your personal cloud without syncing. I'd recommend contacting the support team, though, if you could; we'd certainly like to fix your problem if we can, and it may help other users with similar problems if there are any.