Rough / Double down shift?

[simoncpw]

Hi all,

I recently noticed my X5 4.6iS 2002 has develop the following symptom:
1) cruising in D mode normally on highway, 80Km/h, need to take over a car, floor the gas pedel
2) car auto down-shift one gear (ie: 5th to 4th)
3) but shortly after less than 1 sec, the car will down-shift again (ie:4th to 3th) for a split second, then it up-shift.

So due to this "double down shift" from 5-4-3-4 gear, the car suddenly surge forward abruptly and the RPM goes up to 6-7000

On one occasion, the "Trans Safe Prog" showed up which prevented an gear change. And doing a reset to the adaptive transmission cleared it and gear change normally.

But problem comes back again the next day (without "Trans Safe Prog" so far).

Any suggestion on what this might be?

Thanks.