Thanks for replies so far, just to confirm that the main key is a large key that has a chip in it and this works fine, the spare key is a standard key - have taken apart the plastic casing and it does not contain a chip of any sort.
Cheers :-0
got peugeot 206hdi.will not start any more with spare key,its just normal ,when i do try to start car with spare key ,get engine immobiliser fault on dash panel.ant clue to problem .thanx