Disco 2 immobiliser problem

I hope someone out there can help me. I have a 2003 disco 2 2.5 litre diesel. The key fob opens the doors and when I insert key and turn it the electrics,lights radio etc work fine but when I turn the key to the next position to start the engine the immobiliser kicks in and the alarm goes off. I have tried using the EKA code procedure to override the immobiliser but nothing happens.
Any help or suggestions would be greatly appreciated.

Try the disco section.