Could it be that vBSSO for Wordpress has problems with usernames that contain spaces? VB supports such usernames, and vBSSO creates the Wordpress user with spaces in its name. But e.g. the author link of Wordpress (
http://www.mydomain.com/author/TiKu/) is without the spaces and therefore Wordpress does not find any article.
Maybe spaces should be replaced by underscores for the user name?
Regards
TiKu