Computer name (not hostname) keeps changing

I have a user (10.5 client) on a computer that does NOT have a network account but is receiving DHCP information from a 10.5 server. Her hostname is set in all the usual places to the correct value and when I open up Terminal I am greeted by the correct name... however, in the Sharing Preference pain and at the login screen is shows the incorrect value, and changing it doesn't survive a reboot. I'm pulling what is left of my hair out here. HELP! :)