Cod4 1.7 IP bans

I can't really screenshot, but I play on gameranger using cracked cod 4 to use cheats, but I have gotten IP banned from a few servers now and the problem is I have changed the serial key, new gamranger account, and have used ultrasurf proxy to change hide ip but it doesn't do anything and still comes up with my old ip and banned. Any help on this or why this happens?

Thanks, help is appreciated.

that's probably because those ip's have already been banned.