I would like to know how Domain Mapping Plugin is working

Hello,

I would like to know how Domain Mapping Plugin is working becaus eI have an issue with it.

We do the registration with WHMcs, by creating a primary domain with an existing domain.
It wel creates the subdomain and the plugin seems to make the job (it redirects to the primary domain http://screencast.com/t/fXmftMLMF4ss).

The issue is that the primary domain has no content as normally it should load the subdomain content. We did A records and change DNS namserver.

We already contacted cPanel and WHMcs support, but we don't how the plugin works.

Thank you to tell me.

Best regards,

Xavier