I have had this issue once before and it happened to my wife today. Driving my 2.0TDi DSG in 'D' mode doing about 50 mph and you put your foot down to accelerate. Not hard on the pedal but enough to make it accelerate without changing gear. When you do it, nothing happens, so you put your foot down harder, nothing happens even if you put the box into manual and trying shifting down to 5th. Basically you can't accelerate and the only thing you can do is stop, switch of engine, give it a minute and then start up and all seems fine. Nothing is displayed on dash and nothing logged when checking with a VAS diagnostic tool. Any ideas where to start looking for problem?