Have a 2004 Td6 - in Norway. My problem has been commented also in other forums, so somebody here must have experienced the same.
When the car is cold it pulls right away in R, but when I put it in D it revs for a few seconds (more seconds the colder it is) before anything happens. The gearoil has been changed even though it is a so called life time oil. Still the same. Anybody else? Anybody solved it?

 

Just so you know, it is not lifetime fluid, it must be changed every 30,000 miles or more frequently if used for towing or hard off road trails.
What you describe sounds like a valve sticking in the valve body of the tranny. I would suggest you find a good tranny additive to add to your fluid that will free up that valve or solenoid.
Good luck and let me know how it goes.