Can't login to other sites on network.

I have 3 sites on my multisite network. I'm using domain mapping plugin by wpmu. It was working correctly, but now I can't login to child sites with super admin.

This is the 2nd time I have had this issue. I believe an update keeps screwing me up, but I can't seem to fix it this time. All themes, plugins, etc are up to date.

Site Structure

mainsite.com
mainsite.com/ads
mainsite.com/biz

I am enabling WPMU Support Access to my site.

thanks for any help you can give,

Elmer Harris