Here is my /etc/rc.d/init.d/iptables startup script: 

#!/bin/sh 
# 
# chkconfig: 2345 08 92 
# 

. /etc/init.d/functions 

IPTABLES_CONFIG=/etc/iptables.rules 

# check we have the iptables executable 
if [ ! -x /sbin/iptables ]; then 
 exit 0 
fi 

# check we have the right kernel version 
KERNELMAJ=`uname -r | sed                   -e 's,\..*,,'` 
KERNELMIN=`uname -r | sed -e 's,[^\.]*\.,,' -e 's,\..*,,'` 
if [ "$KERNELMAJ" -lt 2 ] ; then 
 exit 0 
fi 
if [ "$KERNELMAJ" -eq 2 -a "$KERNELMIN" -lt 3 ] ; then 
 exit 0 
fi 

if  /sbin/lsmod 2>/dev/null |grep -q ipchains ; then 
 # Don't do both 
 exit 0 
fi 

start() { 
 # don't do squat if we don't have the script 
 if [ -f $IPTABLES_CONFIG ]; then 
            action "Applying iptables firewall rules:" /etc/iptables.rules 
     echo 
     touch /var/lock/subsys/iptables 
 fi 
} 

stop() { 
 action "Flushing all chains:" iptables -F 
 action "Removing user defined chains:" iptables -X 
 echo $"Resetting built-in chains to the default ACCEPT policy:" 
 iptables -P INPUT ACCEPT && \ 
 iptables -P FORWARD ACCEPT && \ 
 iptables -P OUTPUT ACCEPT && \ 
   success "Resetting built-in chains to the default ACCEPT policy" || \ 
   failure "Resetting built-in chains to the default ACCEPT policy" 
 echo 
 rm -f /var/lock/subsys/iptables 
} 

case "$1" in 
  start) 
 start 
 ;; 

  stop) 
 stop 
 ;; 

  restart) 
 # "restart" is really just "start" as this isn't a daemon, 
 #  and "start" clears any pre-defined rules anyway. 
 #  This is really only here to make those who expect it happy 
 start 
 ;; 

  status) 
 iptables --list 
 ;; 

  panic) 
 echo $"Changing target policies to DROP: " 
 iptables -P INPUT DROP && \ 
     iptables -P FORWARD DROP && \ 
     iptables -P OUTPUT DROP && \ 
     success "Changing target policies to DROP" || \ 
     failure "Changing target policies to DROP" 
 echo 
 action "Flushing all chains:" iptables -F INPUT && iptables -F FORWARD && iptables -F OUTPUT 
 action "Removing user defined chains:" iptables -X 
 ;; 

  *) 
 echo "Usage: $0 {start|stop|restart|status|panic}" 
 exit 1 
esac 

exit 0