Do DHCP Client IDs showup in Airport Utility when Computer Name is shorter than 16 Characters?

My Airport Utility's (version 5) DHCP Clients list used to show the DHCP Client ID for each client, as defined for each connection in System Preferences/Network. I then went and changed the "Computer Name" of my Mac Pro using System Preferences/Sharing. I changed it from "xxxxxxx's Mac Pro" to "xxxxxxxx". Now, Airport Utility's DHCP Clients list shows the Computer Name instead of the DHCP Client ID, for each client. I found that AU will show DHCP Client IDs if I make the Computer Name 16 characters long, one of which is a "-" or a space. I can make the name anything - as long as it's 16 characters long with a "-". What is going on here? Surely, lots of computers have names shorter than 16 chars? Is AU showing DHCP Client IDs for them? I'm using OS X 10.5.6 and Airport Utility 5.4.2. Please don't say I should update. Please do let me know If your Airport Utility correctly shows DHCP Client IDs, AND your Computer Name is shorter than 16 characters (and what versions you are using.) Thanks