Bill - the changes to iptables will be lost when you reboot. To save them, use
iptables-save > /etc/myfirewall
then create a little bootscript that issues
iptables-restore < /etc/myfirewall
If you want to remove your changes whilst the system is running,
flushes all iptable rules. Check out "man iptables" for full info on saving, restoring and flushing iptables.