Fuel Injection problems of the 2007 BMW X3

Since purchase of my 2007 BMW X3 in Nov 2006 the engine hesitated periodically when iaccellerating. I have taken tires to the BMW service center, who drove the car and agreed their was a problem. I was told that there were many cars within a certain lot of VIN numbers , who have the same problem and my VIN number falls within this lot. I was also told at this time, BMW has been notified, but they do not know how to fix the problem. When this problem occurs, the car hesitates in the middle of the street and then surges forward. This is a periodic occurance. It appears that the engine gets the fuel but then does not know what to do with it. BMW service said they would keep in contact with me about fixing this problem but I have not heard from them in over one month. I left another message last week and have not had a return call. Do you have any information about this issue? thank you.