[KLUG Members] changed password on server, now can't login

[John Pesce]

I changed a user's password on my Suse 9.2 NIS server and now he can
only login on a few newer installs of Suse 9.2. He can not login to some
older Suse or any Redhat machines. The only thing I can see different is
he has a longer passwd in the shadow file begining with $2a$.
I believe this is using the newer higher encryption GNU crypt function?
How can I get the other machines to accept the new password?