Domain mapping trouble; Issues with the use of subdomains

I have double and tripple checked the domian mapping plugin install, and I have tried both the A record and the CNAME options:

The ip address of the wordpress multisite is:
174.120.127.45

The site I created is
aarononeill.prowebsitesystems.com and I am trying to map it to aarononeillpainter.com

This outputs the WHMCS install which is on client.prowebsitesystems.com

I have been chatting back and forth with HostGator about this issue and apparently when they remove the sub-domains I have on this account (prowebsitesystems.com) the domain mapping works.

But I recently set up a different account with this exact same configuration and it worked fine.

@Tom Eagles