In the DHCP module of Server Admin, the "computer name" fields of some Macintosh clients might be left blank.
Tip: The "computer name" is set in the client's Sharing preferences.
If a client's computer name contains spaces or non-alphanumeric characters, it might not register correctly with the Mac OS X Server DHCP server. To resolve or avoid this issue, give each client a computer name that contains only alphanumeric characters, with no spaces.