dipstick

Okay here's a weird one.

My 300 tdi's auto gearbox dipstick keeps on popping out about 1-2 inches, has anyone else had this issue.

Just to be sure that it is the right dipstick, can anyone get me the correct length. Sounds silly I know but I brought this home with me from Saudi, and I know there they swap parts or make them as needed.

I didn't even know auto boxes had a dipstick, however, my guess would be it is rattleing out so check that it sits firmly inplace, or there is some pressure building up forcing the stick out.