Zafira 06 Diesel Regenerator

I own a New Shape Zafira 1.9CDTi(150) Auto, and have an intermittant fault??? when in 'Drive' and stopped. The engine 'grunts' and the whole car wants to move forward and I have to brake very hard. AS it is intermitant I have not been able get Vauxhall to find the problem. I am now told by a 'Suit' from Vauxhall, that this is something about the Diesel Regenerator Unit, cleaning itself of soot! It is quite normal, I am told!!!. There is also a bad smell, just like the old burning clutch smell. ANYONE HAD THE SAME PROBLEM??? AND IS THERE A CURE OR ARE VAUXHALL TELLING THE TRUTH.....OR NOT?????