Mine must have been adjusted before I got it.
I was suprised when I read this too, because how well the cruise works in mine was one of the first things I noticed. I tap the button, and that's where it stays.
It even does better about not accelerating down hills than any of the countless vehicles I've driven.
Good info, and thanks for posting it, especially for the guys that are having trouble.

 

My TD5 CC runs like a dream, I've literally done thousands of miles on autoroutes using the CC and much of it towing a heavy trailer. It holds a steady 70 or 80 mph, whatever I set, uphill and downhill. There is only one hill in the Loire when towing a trailer that I have to intervene and give it some right foot 'assistance' uphill.

 

Well it's sorted at long last. I changed the rear wheels to the front so I reckon it has to be a wheel balance issue. Now to get all the wheels balanced perfectly and hopefully the problem will totally disappear. Mind you, it hasn't been tested yet at autoroute speeds of 70-80mph, so that may well be another story.