slk shifting problem

[Island38]

Having problem with the shifting of my 2000 slk 230. Automatic transmission does not shift up sometimes after I have applied hard braking or after I have made a tight turn at low speeds. This does not occur all the time. I can normally get it back to normal operation by shifting into neutral and then back into drive. When this doesn't work I have to pull over, stop, put car in park, shut off the ignition and restart the car. My question is based on this problem description, is it some kind of electrical/switch problem or an internal transmission problem.