I have the identical problem with my 07 X5 4.8
The dealer told me they are aware of the problem and that the engineers in Germany won't get the fix to us until Oct 2008. It has something to do with the computer programing, they said. I think the dealer is lieing to just put me off and maybe I will go away. I am seriously considering hiring a lawyer to make this a recall saftey issue as I have almost hit the person in front of me on several occasions because the car just sits there at the light and then all of a sudden takes off like I pressed on the accellerator big time!. It definitely is a saftey issue and should be a recall situation.
Let me hear from people with the same problems with their BMW transmission. They want all this $$ for the vehicle and it drives like a volkswagon! The ultimate driving machine? I think not, more like the ultimate driving nightmare! I want my money back or a vehicle that operates safely and dependably