Netapp and krb5

Hi all,

I'm trying to mount a cifs share from a netapp 7.0.1.1 share to a
linux box running Ubuntu 9.04 with sec=krb5 and a windows 2000 AD.
But that's failing :

[ 6924.132239]  /build/buildd/linux-2.6.28/fs/cifs/cifssmb.c: Dialect: 2
[ 6924.132246]  /build/buildd/linux-2.6.28/fs/cifs/cifssmb.c: negprot rc -5
[ 6924.132255]  /build/buildd/linux-2.6.28/fs/cifs/connect.c: CIFS
VFS: leaving cifs_mount (xid = 3402) rc = -5
[ 6924.132260]  CIFS VFS: cifs_mount failed w/return code = -5

With the same setup I managed to mount a Win2003 and samba 3 shares
with kerberos.
Using smbclient -k or gvfs2 smb:// is ok with the Netapp share.
I'm not root, mount.cifs have a correct suid.
The /etc/request-key.conf is ok (and it's working with win2003 and samba 3)
The machine account in the AD is the same as the reverse dns name.

I'm running out of option, I could provide a network trace if you give
me a private user email (I won't post that on the list).

Please help,
  Thomas Sondag