Let us know how much ATF you had to put back in and if it cured your problem. This way people searching the web will have a possible fix if they also have the same problem.

Too many time people come to these forums and post a problem, but don't post back when they fix the problem so there are a lot of useless threads on the internet.

Let the car sit over night so that the fluid is nice and cold. Even letting a car sit for a couple of hours after driving it, the fluid in the Torque converter is still hot and like I posted ATF fluid expand when it is hot so you will get a false level. Run through all the gears pausing at each gear for about 30 seconds before adding fluid and when you have top off to make sure all the passage have fluid.

Here's a Youtube video with the correct procedure for filling a BMW trans:

http://www.youtube.com/watch?v=Bxg7aEqty3Y

Did you ever figure out what the problem was?

I have an '01 X5 3.0 that is doing the same thing, but all the time. It wont go anywhere. When it has been off for a while I can start it and roll forward and backwards all day, the second I give it gas it's like it's in neutral.

Hey all just to close the loop on this, It was a little low due to temperature expansion so i added about 1/3 of a quart and it was right as rain. I figure it was temp expansion because there are absolutely no leaks anywhere on the car.