Any ideas why this doesn't work?
/etc/services has the port/npre line, but there's still an error in /var/log/messages.

Thoughts?

[root@dggs-earth etc]# cat xinetd.d/nrpe 
# default: on
# description: NRPE (Nagios Remote Plugin Executor)
service nrpe
{
           flags           = REUSE
        socket_type     = stream    
    port        = 5666    
           wait            = no
        user            = nagios
    group        = nagios
           server          = /usr/local/nagios/bin/nrpe
        server_args     = -c /usr/local/nagios/etc/nrpe.cfg --inetd
           log_on_failure  += USERID
        disable         = no
    only_from       = 204.90.103.9
}
[root@dggs-earth etc]# ls -la /usr/local/nagios/bin/nrpe 
-rwxrwxr-x. 1 nagios nagios 131764 Mar 28 13:25 /usr/local/nagios/bin/nrpe
[root@dggs-earth etc]# ls -la /usr/local/nagios/etc/nrpe.cfg 
-rw-r--r--. 1 nagios nagios 7336 Mar 28 13:25 /usr/local/nagios/etc/nrpe.cfg
[root@dggs-earth etc]# egrep nrpe services 
nrpe          5666/tcp                        # NRPE
[root@dggs-earth etc]# egrep nrpe /var/log/messages 
Mar 28 13:26:29 dggs-earth xinetd[8918]: service/protocol combination not in /etc/services: nrpe/tcp
Mar 28 13:36:26 dggs-earth xinetd[9425]: service/protocol combination not in /etc/services: nrpe/tcp
Mar 28 13:38:48 dggs-earth xinetd[9448]: service/protocol combination not in /etc/services: nrpe/tcp
Mar 28 13:48:49 dggs-earth xinetd[9492]: service/protocol combination not in /etc/services: nrpe/tcp
Mar 28 13:50:57 dggs-earth xinetd[9534]: service/protocol combination not in /etc/services: nrpe/tcp
[root@dggs-earth etc]# uname -a
Linux dggs-earth 2.6.32-220.el6.x86_64 #1 SMP Tue Dec 6 19:48:22 GMT 2011 x86_64 x86_64 x86_64 GNU/Linux
[root@dggs-earth etc]# telnet localhost 5666
Trying ::1...
telnet: connect to address ::1: Connection refused
Trying 127.0.0.1...
telnet: connect to address 127.0.0.1: Connection refused
[root@dggs-earth etc]# netstat -at |egrep nrpe
[root@dggs-earth etc]# which xinetd
/usr/sbin/xinetd
[root@dggs-earth etc]# ls -la /usr/sbin/xinetd
-rwxr-xr-x. 1 root root 174456 Dec  7 12:09 /usr/sbin/xinetd
[root@dggs-earth etc]# ps -ef |egrep xinetd
root      9534     1  0 13:50 ?        00:00:00 xinetd -stayalive -pidfile /var/run/xinetd.pid
root      9982 14581  0 16:18 pts/3    00:00:00 egrep xinetd
[root@dggs-earth etc]#

Do you have iptables or a firewall running on the server?