If you’re upgrading from an old version of Ubuntu to Jaunty (9.04) and using Empathy Instant Messenger, then MSN Client will never work with you and You’ll get a “Connection Error” Message .

To Solve this issue All you have to do is close Empathy and Go to Terminal and reconfigure pymsn to get work again , just like that :

dpkg-reconfigure python-msn

And then Start Empathy again and your MSN Account will work for you

Source : Launchpad Bug #338891