Hi Paul,
Yeah, it looks like the Master Server registration is failing. I see two errors in the log -- one is that the server is sometimes unable to connect back to your FSHost at all, and sometimes it's able to connect to your IP, but it's getting some other web server instead of FSHost.
Here are a couple of things to try... First, run ipconfig to find out what your internal IP address is. This will probably be something that starts with 192.168. For example, it might be 192.168.0.101. Then you need to configure your router to forward web requests to your computer. I'm not sure which router you have, but here's a page that describes how to do port forwarding for various models:
http://www.portforward.com/routers.htmYou want to forward the HTTP port, which is TCP port 80. Put in your internal IP address for the machine it should forward the port to.
Another thing to check is your external IP address. Try going to:
http://www.whatismyip.com/And see if it's the same IP that FSHost is reporting.
Another thing you can try is to change the port FSHost is using. Go to Options / Remote Access and change the port from 80 to 81. Or try other ports such as 1000, 5000, etc.
Let us know all the details of what you try, and I'm sure someone can help.
Russell