Please take note… per our announcement on August 29, we will shutdown Version 4 of the API today.
Please make sure you have migrated your applications to Version 5 or 6 in order to ensure uninterrupted service. You can find more information about Versions 5 and 6 (including the release notes) at http://www.google.com/apis/adwords/developer/index.html.
-- Rohit Dhawan, Product Manager
