I have just installed a new kernel (2.4.27). I patched the kernel to handle pptp/gre conntrack. I also installed iptables 1.2.11 on this server, after the kernel build I installed iptables and that went through fine. When I restart the server the new kernel works great, but iptables gives me an error of 'iptables: Invalid argument' for any -t nat rules. Have I missed an option on the kernel rebuild? Paulo