self-hosting with comcast dns
I already have a webserver that I want to use, but I'd like to move from my current dns, to comcast's dns. I tried to do it following these instructions: http://businesshelp.comcast.com/help-and-support/Email/using-own-domain-business-class-email-web-hosting/
However, I have a couple of questions:
1) If I set up DNS registration with comcast, I don't have to use comcast's hosting plan, correct? I already have the server set up on the IP it needs, just with another dns provider.
2) When I go here: https://businessclass.comcast.net/Secure/ManageServices/SetupDomainName
It says: "unable to register the domain, please contact your system administrator"
What do I need to do, in order to find out why this wont transfer?