[X2Go-User] Kerberos and X@Go Mac Client

I’m having trouble with Kerberos authentication with a Mac client. I am using x2goclient-4.0.4.0-preview2 on a Mac running OS X 10.9.5, connecting to Ubuntu 14.0.4 running x2goserver-4.0.1.19. Here are the symptoms:

1. Connecting with kerberos and ssh works fine. I run kinit to get my tgt, and then ssh works without prompting for any sort of authentication.
2. When I tell X2Go to authenticate using kerberos, it connects without apparent error, but my keyboard mapping is bizarre (and pretty much useless).
3. When I tell X2Go to use the default authentication, it waits for some time (maybe 30 sec or 1 min), and pops up a dialog box, asking for a passphrase to decrypt a key. Whether I click OK or cancel, it then pops up a new dialog box, with the following text: "Received SSH_MSG_DISCONNECT: 2:Too many authentication failures for dritch Invalid state in ssh_userauth_kbdint”
4. When I configure an ssh key pair for passwordless login, and configure the X2Go client to use default user authentication, all works fine.
5. Before, when I used the 4.0.3.2 release client, it had very similar behavior. However, in that case, when connecting using kerberos authentication, it also popped up a dialog box with an scp error message.

Am I doing something wrong? How can I make this work?

Thanks!

David