Hi, I have a 2000 P38, ive had exactly the same problem with the lockout and having to use the EKA to start the car, after having the keyfob replaced and the imobillser checked on diagnostics i had it happen again!!
We think now it may be as i live near the severn bridge and that the radio frequencies used in the TAG system could cause problems to the Range Rover
Ive been told to have a Modified Receiver fitted to cure it,
Anyone else had one fitted??