NIS problems

[Vulpes Velox]

I've recently set up a NIS server on my lan. All machines are running
freebsd 4stable.

I have added the nisdomainname and nis_client_enable lines to the
client machines along with the correct lines on the server in rc.conf.

I have also added +::::::::: to the end of /etc/master.passwd and
+:*:: to the end of /etc/group.

Ypcat passwd all the correct usernames, but I can't login or su as any
of them.

On the login if I try to login using one, I eventually get the message
"login: Login timed out after 300 seconds" awhile after it kicks out
"Login incorrect"

Any one have any idea what is going on?