i had similar problems with my x5 4.4 2006. the issue was when i was slowing down and going from 4th to 3rd gear, the car would suddenly accelerate. another issue was that there was a delay from the start and very slow transmission up shift.they were trying to fix it...software but could not. two months later, the car started making weird rambling noises that authorized dealer tried to repair three times. after long discusssion with the dealer and BMW of North America, they are replacing my x5 4.4 2006 (7 month old 10, 000 miles) with a 2007 x5 4.8i. i just hope that this new car will be "bug free" and i will not have any more problems with the transmission. my wife and my daughter both have an x3 (2005) and the transmission is absolutely flawless.

thank you,
alex

ps iam glad to become a new member of this fascinating forum