HI Steve,
Its not the fob as I have 2 which I use at random so each one gets used almost every other day and they both work, also the immobiliser light isnt flashing on the dash.
I've phoned Subaru who said I need to try and find the 4 digit code for the keypad to over-ride the immobiliser so fingers crossed i can find that tonight.
Cheers,
Chris.