New subdomains are not mapping to their proper URL

I have turned on domain mapping... I turned off all the settings for DNS domain name checks, etc. because I have alot of domains right now that are just sitting there and will take time to propagate.

I just created my first subdomain... fattenmeup.thedomainbrewery.com . I didn't see anywhere to tell the site that the url to be associated is fattenmeup.com. So that's probably part of the problem.

Can you please tell me:
1. How do I associated the subsites URL?
2. Why isn't this working? I can't even go to fattenmeup.thedomainbrewery.com, which should work regardless of if there is another URL I'd like to associate it with or not.

I've give you support access to my site. I hope you can help me.

Thanks,
Tom