[Samba] Kerberos enc type [xx] failed

[Ephi Dror]

Hi All,
 
I am getting Kerberos "enc type" problem that I can't explain:
 
[2005/06/11 11:41:29, 1, pid=29355]
libads/kerberos_verify.c:ads_keytab_verify_ticket(61)
  ads_keytab_verify_ticket: krb5_kt_start_seq_get failed (No such file
or directory)
[2005/06/11 11:41:29, 3, pid=29355]
libads/kerberos_verify.c:ads_secrets_verify_ticket(193)
  ads_secrets_verify_ticket: enc type [16] failed to decrypt with error
Program
lacks support for encryption type
[2005/06/11 11:41:29, 3, pid=29355]
libads/kerberos_verify.c:ads_secrets_verify_ticket(193)
  ads_secrets_verify_ticket: enc type [3] failed to decrypt with error
Program lacks support for encryption type
[2005/06/11 11:41:29, 3, pid=29355]
libads/kerberos_verify.c:ads_secrets_verify_ticket(193)
  ads_secrets_verify_ticket: enc type [1] failed to decrypt with error
Program lacks support for encryption type

It used to run well but suddenly it happened out of the blue.
 
I would like to ask what are the things that can lead to this problem.
 
Just a quick background:
1. My samba version is 3.0. 6 (will switch to latest soon)
2. My Kerberos version is krb5 1.2.7. 
4. Samba joined active directory that  has one KDC running win2003 (not
sp1)
5. I switched between different domains and join as ADS and domain many
times, could it contribute to this problem?
 
At the moment, I can't switch to latest krb5 package. What is the
minimum Kerberos version required by SAMBA?
 
I have seen someone mentioned Microsoft Hot Fix for Kerberos, is this
what I need here.
 
Is it something on the SAMBA server, a file or krb command I can run to
clear things up when it happens?
 
I appreciate very much any hint in this area.
 
Cheers,
Ephi