Mac OS X Server 10.4.6 and later include changes to the command line utility "changeip" such that you must now use a fully qualified domain name (FQDN) with the command.
Previously, changeip could be invoked with the server's short name, like this:
changeip /LDAPv3/127.0.0.1 10.0.1.1 10.0.1.2 testserver testserver2
Using the FQDN in Mac OS X Server 10.4.6 or later, your command would look like this:
changeip /LDAPv3/127.0.0.1 10.0.1.1 10.0.1.2 testserver.example.com testserver2.example.com
Before running changeip, be sure you have updated the server's hostname in DNS to match the hostname provided to changeip; otherwise errors will be logged in system.log, and services may not function properly.