I had this same issue with my 2004 4.4i. I got it back yesterday from dealer and they updated both the ECU and the TCU (I think) transmission software. Yesterday driving home was very smooth. This morning (16 degrees) the car didn't hesitate and buck when I drove to work. I'm a bit worried tho as they found the oil 1 quart low and that makes me nervous...I had complained about valvetronic ticking when it was cold. With the addition of oil it didn't do that this morning. I don't have the paper work handy but I'll look and see what TSB they mentioned.

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2007 328i Sport, Monaco Blue
2011 X35D - sold -Space Grey
2004 X5 4.4i - sold - Kalahari Beige
2001 X5 3.0i - sold - Pearl Beige
2006 325i Sport, Sonora Beige
2000 323i - sold - Sienna Red