Recently, I moved over to a new host with a dedicated box and I had to setup the nameservers for my domain kpsolution.com. In Godaddy’s domain manager, I tried to change the nameservers to my domain like ns1.xxxx.com and ns2.xxxx.com, but got an error that “Nameserver not registered“. This was puzzling as I had setup the slaves dns entries on my server correctly but Godaddy complained that “Nameserver not registered”.
Then I found that in the lower left corner, there’s a box with “Host Summary”. You have to add your nameservers entry in that box first. So click on “Add” besides “Host Summary” and it will present you another dialog where you can enter your subdomain and the ip address to point to your server. Once you have added your nameservers in Host Summary, then you can click on “Manage” besides “NameServers” and add your nameservers ns1.xxxx.com and ns2.xxxx.com there and Godaddy will happily accept it!!
Hope this saves you your time and help you avoid pulling your hair!!!