Update -
Had the rouge 'Brake Light Failure' fixed at dealers today - they changed the convenience unit that runs the cars lighting system - this meant a reprogram of the car to synch it up. Soon as I drove away I realised this had blanked my 'ChippedUK' remap..
Will have to call them tomorrow to get it booked in for a re-flash.. forgot how mellow they are stock, can really feel the difference.