Join Kerberos button missing

I'm trying to make a 10.5.5 server to bind and authenticate to our AD, but the Join Kerberos button is missing. In Server Admin the role is Connected to a Directory System. The button below says Open Directory Utility. In Directory Utility the AD server status is "This server is responding normally. This server is not in your authentication search policy." Under Services the Active Directory configuration shows the server as bound - AD Forest, Domain, and Computer ID are grayed out and the button says Unbind. Under Search Policy the Authentication is set to Custom path, and the AD server is listed below /Local/Default and /BSD/local. After successfully binding, the popup told me to go to Server Admin and click the Join Kerberos button in Open Directory settings General tab, but the only available button is still Open Directory Utility. Any idea what's wrong?