Kerberos/GSSAPI auth weirdness?

[r3pek]

Hi list!

I'm migrating my server into a new REALM (INT.R3PEK.ORG) from an old one 
(R3PEK.ORG). This is a completely new install and configuration, so no 
leftovers exits.
The machine is correctly register into the REALM and users are able to 
login without a problem.

Now, when I try to login using a Kerberos ticket, for some reason that I 
can't understand, dovecot is looking for a ticket on the old REALM. 
Maybe because of the email domain (which stayed the same)? This is the 
error message I see on the clients:
"Failed to authenticate: Server krbtgt/R3PEK.ORG at INT.R3PEK.ORG"

The one it should be looking for is krbtgt/INT.R3PEK.ORG at INT.R3PEK.ORG, 
but I can't seem to figure out where the problem is.

# doveconf  | grep -i realm
auth_default_realm = INT.R3PEK.ORG
auth_realms = INT.R3PEK.ORG


What do I need to change to make this work?