samba - Jun 2014 - Samba with Bind and GSSAPI: configuring TKEY: failure

I tried to set up Samba using a separate Bind as described in the howto. 
It worked about the way it was described there. Since smaba roots in 
/srv/files I had to link /srv/files/private to /var/lib/samba/private in 
order to make the DLZ find the smb.tld files. However, using the GSSAPI 
update I find teh following in the syslog whens starting bind9.

Jun 10 00:26:42 samba named[3938]: default realm from krb5.conf 
(AD.EXAMPLE.COM) does not match tkey-gssapi-credential 
(DNS/samba.ad.example.com)
Jun 10 00:26:42 samba named[3938]: configuring TKEY: failure
Jun 10 00:26:42 samba named[3938]: loading configuration: failure
Jun 10 00:26:42 samba named[3938]: exiting (due to fatal error)

According, to several mailing list entries the first line is not 
necessarily an error. It's strange though, since I use the krb5.conf 
generated by the provisioning.

Any idea how to troubleshoot what exactly bind is complaining about?

Thanks for your help,
  - lars.