Have you thought about the default trace as schema changes are already recorded there and easily available without the need for a ddl trigger. In fact Microsoft provides a schema change history report available as part of the basic installation. Why re-invent the wheel?

Again DDL triggers are part of the toolset and available to be used when most appropriate but a bit overkill to use a DDL trigger to get information on something that is already directly available.

This has also been documented in a good article from 2008

http://www.sqlservercentral.com/articles/SQL+Server+2005/64547/