[Plugin: WordPress MU Domain Mapping] Administrators lost there right after visiting a site example

Hello,

Administrators on its personal site no-mapped lost there right on its personal site after visiting a site example mapped where its link is linked in a forum on the main site of the network and this link is displayed with its www.

I have tried 3 times installation of wpmu mapping and the same problem re-comes each time. I have configured the plugin and after configuration the mapped domain work but I think, I forgot something in apache conf or in dns for the mapped domain and the problem comes from me.

WordPress

* Configured network: sub-domain install.

Plugin

* simple:press forum 4.5.1 (where the mapped domain is linked on the main site and all sub-blog of administrators have this forum-plugin installed too)
* connexion plugin theme-my-login (on all sites)

What’s is wrong, my apache config ?

Thx in advance for any help

https://www.ads-software.com/extend/plugins/wordpress-mu-domain-mapping/