I have the same thing Neil on my 06' 320d. Only happens occasionally though, and everytime it does I get the tut from my wife thinking its my driving. I actually thought it was 'my' driving until I read your post!
Im getting my new eff dynamic 320d edition on the 1st sept, so will be interested to see how it compares to my current one. Not sure if im going to get on with the whole stop start thing?
I also second the lack of power issue on occasions, it feels as if I do not give the engine enough revs and it dies down? Maybe thats exactly what it was.....
