Check this:
http://support.apple.com/kb/ts3560
When they delete this, here is the summary:
Check this file on the client: /Library/Preferences/edu.mit.Kerberos See that it is not using ip addresses for lookups (i.e. use hostnames and dns). If it is and or it needs fixing, change it on the server: In Workgroup Manager, open Preferences, make sure the Show "All Records" tab and inspector checkbox is checked I.e. make sure you can see the super secret options.... (e.g. pulldowns etc...) Get to the Config->KerberosClient->XMLPlist Check out the "KADM_List and KDC_List arrays", and replace ip's with hostnames. Update the id at the bottom and save.