I hate digging up old topics but since this is a howto and what I used to change my server IP there are a couple more things that need to be considered.
-Changing your IP in the WebUI is not enough, edit /etc/sysconfig/network-scripts/ifcfg-eth0
-Make sure your glue records are correct at your registrar. I'm using CWP to manage DNS and forgot to update the glue records besides editing in DNS functions.
-If using CWPpro, update your IP in your account, I forgot about that too
-Would be nice if there was an official howto