Greg,
I also don't see this behaviour on my HomeHub running firmware release 6.2.6.C.
From the internal network, if I type the WAN address I get the web
server and if I type the LAN address of the router, I get the HomeHub admin pages.
You can also check what you would see from the Internet by using an anonymiser service such as:
http://anonymouse.org/anonwww.html
HTH,
Peter.