Sorry to be late on the scene John, but from reading about DPFs elsewhere it would seem that many do indeed experience various noises whilst the regeneration is taking place, some even mention extra smoke when booting it and the most common advice seems to be not to turn the engine off during regeneration.
Thankfully my model is not troubled with a DPF, but I had one on a previous car and I found it to be a damn nuisance. Personally I think they're more trouble than their worth but some would argue that if you look after it then it will look after you; either way, if you've got one I'm afraid you're stuck with it. Google it and you'll get all sorts of views.