Have you had a fuel system flush? I had one a little after it started happening and it didn't really help. A Motorvac if it matters.

One poster on Bimmerforums at http://forums.bimmerforums.com/forum...=1#post7238767 said that his 06 4.4 had this problem and his service department replaced all of his injectors and the problem went away. I just posted there to see if it stayed away.

I would think that the fuel system flush should have cleaned the fuel injectors well enough that if that was the problem it would have been fixed.

Thanks for the info on what it isn't, I was thinking of throwing cam speed sensors at it. Well now i can save that money for something not on your list.