I am suffering this issue too
Picked up my car March 2013. This year on the service (3rd March) I asked them to check the juddering gearbox.
Report back that this will need to be looked at under warranty and they suspect it requires a 'clutch pack'.
Phone call a month later to say they cannot locate any available clutch packs to book the car in. Sky Ford in Hemel Hempstead have phoned a couple of times since to say they have not forgotten about me, it is jsut there are no parts available.
I am left with a car I am slowly beginning to hate driving.