Kerberos retry count exceeded Panther server, Jaguar client

Hi, I am trying to configure an Xserve G5 (10.3.9) as Open Directory Master and Kerberos kdc. DNS in the same server is working, and so does LDAP and Kerberos , when I log in from another Panther client. But I have a Jaguar (10.2.8) client , and from that client I cannot login using Kerberos. The kinit command asks for the password, and after some 30 seconds returns a “retry count exceeded” error. The same edu.mit.Kerberos file works fine from Panther. I already browsed the net looking for a similar problem and found it may be related to tcp/ip connection problems, but from the Jaguar G4 I can access the DNS and log in to the server via rsh.
Can someone give me some help?
Thanks in advance,

Jorge