Gearbox problems Audi A8 4.0 TDi Bj 2003

Hello to all professionals and experienced with similar problems or possible solutions!
Signed up here after reading a variety of reports, but found no comparable help.
First to my Audi, in August 2006 he was bought by a re-purchaser who bought him directly from an Audi dealer in the Black Forest where he was used as a demonstration car Nov 2004. I acquired it with a mileage of 47,000km. Per Dato, I have just under 66,000km on the clock!
Problems have already emerged immediately. after the purchase on which I did not give any greater importance. Because when the engine is cold (outside temperature independent) and I constant approx. ==References====External links==* Official website 3-5 Km/h up and down without changing the position of the accelerator pedal. In December, an Audi workshop replayed a software update to me, which caused the error for approx. 5 days. ==References====External links== 70km/h. In addition, there is now another problem in driving, for example. At a traffic light, the automatic switches "massive" into the first gear at a standstill, which almost feels as if you have driven over a piece of wood (independent of the operating temperature). However, no other noticeable mechanic sounding disturbing sounds.
Maybe someone knows something about my problems.
Greeting Frank