Hi
I have a clk 430 with the same geraboxand when cold i have the same problem , the problem is only when teh car downshift between 2nd to 1 st.
to avoid this I normally swithc to W untill teh car is hot in this way the car does not downshift in 1st .
When i reaxh operating temperatore is wor^king fine and i switch again to S.
I think that tjhe only solution is update the software but MB wokshop is expansive here in switzerland.........