Hi carl. unfortunatley you can't by-pass it. You say your old key is reluctant to work? They usually work or not. In the key is a glass component that houses the immobiliser sensor, it is possible to swap it into the new key with care. By the year of manufacture, I would say you have the pear shaped fob. It has to be taken apart to remove the sensor. You will find the sensor mounted in rubber, gently ease it out and swap it with the one in the new key. Dont get them mixed up!!. You will have to reprogramme the remote locking again afterwards. That should sort your problem. The other answer is to take it to a Ford dealer for programming, an easy job when you have the right gear!!
Paul
January 2008