The online topic is 2006 version. We both confirmed both topics are ok! Refer to follows.
Dear XXX,
Thank you for your interest in Columbia Business School. We encourage all applicants to respond to the essay topics on the 2007 application. However, if you have begun work on the 2006 essay topics, we will accept your responses, because we recognize the time and energy that goes into preparing the application. Equal consideration will be given to both sets of essay topics.