Hallo boy,
i have installed :
red hat 4 AS
and the cluster suite :
clumanager-1.2.3-1.i386.rpm
ipvsadm-1.21-9.ipvs108.i386.rpm
piranha-0.7.6-1.i386.rpm
redhat-config-cluster-1.0.0-5.noarch.rpm
rh-cs-en-3-1.noarch.rpm

I want use a Gui utility and without other step i launch a "redhat-config-cluster" command .
But it isn't work and in output this error :

[root@rhux ~]# redhat-config-cluster
Traceback (most recent call last):
File "/usr/sbin/redhat-config-cluster", line 46, in ?
from clusterpkg.cluconfig_module import cluconfig
File "/usr/share/redhat-config-cluster/configure/clusterpkg/cluconfig_module.py", line 11, in ?
from clusterpkg.services_module import services
File "/usr/share/redhat-config-cluster/configure/clusterpkg/services_module.py", line 3, in ?
from clusterpkg.service_module import service
File "/usr/share/redhat-config-cluster/configure/clusterpkg/service_module.py", line 4, in ?
from clusterpkg.service_device_module import device
File "/usr/share/redhat-config-cluster/configure/clusterpkg/service_device_module.py", line 7, in ?
from clusterpkg.util_smbconf_module import smbConf
File "/usr/share/redhat-config-cluster/configure/clusterpkg/util_smbconf_module.py", line 55, in ?
FILE_HEADER = _("""
NameError: name '_' is not defined

no idea what the question is.

if its supposed to be "why is this broken?" the answer is: who knows?

its a bug. redhat is buggier than most, in my opinion.

The command for cluster config in RHEL 4 is system-config-cluster.
And the cluster suite is kernel specific . check if the cluster suite is supported on your kernel.