In the days before the Shared Registry System there could not be multiple nameserver host names for a single IP address. If you attempted to create a new one, the info just went to the old hostname.
After SRS, this was still the case. In fact, this was the case pretty much the last time I typed the wrong IP number in the blank.
Tonight I connected the same IP number to two different nameserver hostnames. Is this a bug in the new SRS release or is this a new functionality of the system?
This was a registry limitation that was removed quite a while ago (almost two years), at least in the case of the .com/.net/.org registries.
Many people, including me, have been using multiple registered nameserver names pointing to the same IP address for quite a while with no problems. It's definitely not a bug; it's a supported feature, so you can use it safely.
-- Robert L Mathews, Tiger Technologies http://www.tigertech.net/