Saving Settings - Bt Voyager

Hi

After putting a WEP key on my network i have gone round each of the computers and set it up beisdes one. The computer with ME i have changed the settings in the Voyager Utility to open key 128bt so the internet works. Everytime i shut down the computer and turn it back on again, it changes back to auto and the internet will not run and i have to keep changing it everytime i want to use the internet from auto to open.
Does anyone know why this? and why it will not work everytime i turn the computer off then on again?
thanks