Issues With Site Admin on Subdirectory Install

We have a fresh install using subdirectories and the http authentication plugin to use CAS authentication. I created a site and then installed the domain mapping plugin which works great on the front end, but trying to access the various site admins it redirects you to the default site admin.

For instance:

Say the default domain is defaultsite.com and I have a subdirectory site setup at defaultsite.com/mysite

Prior to installing the domain mapping plugin I was able to access defaultsite.com/mysite/wp-admin

After installing the domain mapping plugin and setting up mysite.com successfully pointing to defaultsite.com/mysite I am no longer able to access the site admin for that site, mysite.com/wp-admin redirects to defaultsite.com/wp-admin and defaultsite.com/mysite/wp-admin redirects to defaultsite.com/wp-admin

Has anyone experienced this before? I’m pretty sure I have the right settings.

http://wordpress.org/extend/plugins/wordpress-mu-domain-mapping/