i know your pain, i used to use the orange live box, and the biggest problem with it is its a rubbish piece of kit, took so much fiddling to sort it all out, had similar problems, and if you changed something on one it threw the network out.
my advice if you ever plan to change ISP go with the o2 wireless setup. there box was a breeze and xbox connected without any fiddling in setup. and the internet works 10 times better than when with orange, only got 2mb with orange get 8mb with o2