An updated redhat-config-nfs package has been released for CentOS-3

There is an updated redhat-config-nfs package for CentOS 3.3 (and added to 3.1)

https://rhn.redhat.com/errata/RHSA-2004-434.html refers

Updated file is :-

redhat-config-nfs-1.0.13-6.noarch.rpm

in updates/i386/RPMS/

This is available at http://mirror.centos.org/3.1/ and should be on all mirrors within a few hours.

To update to the latest version 'yum update redhat-config-nfs' should be sufficient.