Hmmmm, another option worth considering is to do what esacjack mentioned in another thread, and basically just have your gateway hand off traffic to a wireless router. The capabilities of the 2wire frankly suck, and you might have a much easier time setting up the standard wrt54g, or whatever you might have lying around.
just out of curiosity, when you changed the address, did you use the port when connecting via browser?
for example, it used to just be 192.168.1.50, but when you change the port it needs to be 192.165.1.50:8080