This is a warning to anyone still using version 12 of the Google AdWords API. Google has announced in a Google Groups thread, amongst other places, that they will stop supporting it on February 23, 2009.
AdWords API version 13 has been available since October and if you have not yet upgraded, it is time to do so now.
Jeff Posnick from the Google API team said, "the latest versions of the publicly available official Google client libraries all support version 13 of the API, so if you're using one of those, please check the relevant README file for information on how to switch from version 12 to 13." However, the Perl version is not maintained by Google and the third party developer has not yet upgraded it. Google has confirmed that it will be upgraded before the sunset date.
Forum discussion at Google Groups.