Domain Mapping Subfolder Install

This is my first Multisite install on a VPS.

I installed Multisite in a folder wphems. I am using your Domain Mapping plugin.

At the domain registrar I have set the * and WWW A records of itsapinz.com to point to the IP address of wphostengine.com

In your plugin I have tried to map itsapinz.com to the site http://wphostengine.com/wphems/itsapinz/ but the plugin automatically adds folder directory to the mapping so it shows http://itsapinz.com/wphems/ mapped to http://wphostengine.com/wphems/itsapinz/

How can I get this to eliminate the install folder mapping so the root domain maps to the proper site?