General :: Removing / Disabling Firewall Happens Temporarily

I tried following the instructions in this link to disable and remove iptables firewall using commands:

# service iptables save
# service iptables stop
# chkconfig iptables off
# iptables -F
# iptables -X
# iptables -t nat -F
# iptables -t nat -X
# iptables -t mangle -F
# iptables -t mangle -X
# iptables -P INPUT ACCEPT
# iptables -P OUTPUT ACCEPT

Its seems to work temporarily and then the firewall gets enabled again by itself even without restarting.