Changing Network Passwords on 98 clients

Why can’t I get the passwords to update on the domain controller when I change it on a Windows 98 client. In the Control Panel, I go to passwords and change other passwords, follow the instructions. it says it changes it, but it will not update on the PDC and the only password that will work to log in is the original password. I have to go to the PDC and update the password manually. Can someone help me with this problem?