I tried to register a fob on a 2008 gx470 and it looks like the maxi wiped the immo clean of transponder codes. Not even the master key works anymore.

 Had the maximum number of programmed keys already been reached that attempting to simply add another key had the affect of wiping the immobilizer clean of transponder codes without selecting clear all keys? Did you keep all the other keys including other vehicle keys far enough away from the vehicle you were attempting to add the key?