Asty,
Thanks for your input. I'm beginning to think it's somethignt hat needs to be done in the workshop.
I've now spoken to 9 different dealers service departments and still I'm no nearer to getting an answer. A couple have actually said it's in the manual and pretty much put the phone down on me!
I've finally spoken to someone who has promised to get to the bottom of the issue and get back to me in a few hours so I'm keeping my fingers crossed. But then again, I've heard that before and they never got back to me.
If it is a workshop job then so be it. Although I would find it somewhat short sighted (if you set aside the fact that it's more revenue for the dealers aside) if it is the case.