Here's what is going on. Your external request is going to your router, out to the internet and doesn't know to come back. I think you will find that you can not get to any of your external ip's from inside your network if you try. based on the limitations of a netgear router I would say that you may be stuck with this. if you had a cisco router I think you could create a static route on your public interface to handle external requests that are attached to your network. I had to do something like this on my PIX firewall at work in order to handle external requests within our network with ip's that belonged to us.
Solution. Create a host file on the server and give it a friendly name, or simply use the machine name. it could look something like this:
192.168.0.10 www.mycoolserver.com
you could then get your your web server internally by entering the following:
www.mycoolserver.com:81" target="_blank">http://www.mycoolserver.com:81
of course, this would only work inside your network. You'd have to use the external ip address from your home.