Sorry my german is verry poor,
But I also have a cold start problem with the Corsa OPC.
When i start the car (cold start) it start good, but when i start to drive it almost fall out. After 300-500 meters he car runs good.
when i start the car (cold) and let it run in auto-choke program (1minute) then arround 1100-1300 rpm you feel a little unstable running. Then the rpm decrease to 750 rpm and i can drive without any problems.
The car got a new software update from opel 03-2010. So the car is original and no EDS tuned.
airfilter is new 2500km, gasoline RON 98, 29000km, last service at 27000km