First you should look at the domains DNS using: http://www.intodns.com

If you see any glue record errors, it is because you need to register your reseller nameservers at your domain registrar with the IP addresses specified in your account welcome email before you use them to host any domains.

Please keep in mind, registering nameservers is not the same as just updating the nameservers for your domain.

Most domain registrars have an option in their control panel to register or create child nameservers or glue records.