I imported content from Joomla/Wordpress into vBulletin 4. I'm now in the process of scrubbing the content. The articles show imported_username as the author. Logically, I merged imported_username into username. I expected the articles to follow, but they did not.
CMS articles do not show an author and there is no way to edit the author (that I'm aware of). This also doesn't allow me to enable comments on hundreds of articles -- I guess since there is no associated author.
I ran a few Update Counters -- rebuild users, rebuild threads.