cannot renew ip address

Not quite sure if this is what you mean, but typing 'my ip' into Google givs a list of web sites which can report the IP if the user. The 'synopsis' provided by Google is generated by Google accessing the web site, and thus reports Google's own IP address. If you then click through to the site itself, you get 'your' IP address, but I'm not sure whether this is your own address or that of the NTL proxy server - it may even depend on the site you go to. If it's the address of the proxy, it probably won't change.