That UI has last been updated 12-21-2005, ie a little eternity ago. The EverQuest II interface is constantly evolving and custom interface pieces sometimes need to be updated to stay compatible.
If you are looking for a complete set, it is pretty imperative to select one that has been updated fairly recently. If you are just looking for specific windows the chances that they still work after a long time are higher (because SOE may not have changed the mechanics of that specific window).
PS: Changed your thread title so people know what this is about.
