I've had some problems with the auto downshift before. Just before I come to a stop, when slowing down, the gear downshifts abruptly and you can feel a jerk. It's like a delayed downshift. It happens only once in a while, and when it does, it goes on for the entire drive until I switch off the engine. On the next startup, the problem would be gone until it decides to come back again some other time.
At first I thought it was the first signs of a transmission problem...big $$$.
Then I thought...if it doesn't happen all the time, and especially after restarting the engine the problem's gone, it may be something to do with a software glitch.
I checked with BMW on software updates and service bulletins...nothing for my year and model. Then I got some advice from some people about taking time to let the computer system loadup when starting up the engine, and letting it shutdown when cutting off the engine...just like you would your PC.
When you insert the key into the ignition switch...wait and listen to the sound of the system loading...maybe 10 secs...then turn the key to start.
When you turn the key to cut off the engine...wait and listen to the sound of the system shutting down...then remove the key.
I don't know how far this is true, but it makes sense.
Most of all...miraculously, I have not had the problem eversince!
Now, no matter how much in a hurry I am, I would go thru' the start and shutdown ritual. It could be a pain sometimes though...