Nope, tried everything, all to no avail. When I started it up today the FM (Radio 2) reception was very poor on what I know to be the correct optimum frequency. I can only assume the unit is faulty or it's linked to problem with the ariel. Time to have a chat with the dealer I think!
I'd agree that the radio or installation is faulty. Since I deselected Traffic it's picking up and locking onto all the stations.
Still like to have Dab though.