Samba4 beta7 spn NFS problem

[steve]

Hi
I want to add the nfs/myhost principal to /etc/krb5.keytab but since 
beta 7, samba-tool domain exportkeytab only adds the (des-cbc-crc) 
principal:

1 08/28/12 18:12:16 nfs/hh1.hh3.site at HH3.SITE (des-cbc-crc)

I added the spn like this:
samba-tool spn add nfs/hh1.hh3.site nfs-user

How do I get the (arcfour-hmac) and (des-cbc-md5) keys as in previous 
versions?

Thanks,
Steve