Hello, I'm back again,
Now I have permutated the dependencies. It is obviously the case, that ATItool hardware monitring function does not go together with Speedfan 1.17. Apparently the try to get information fom the monitoring chip and interfere with eachother.
Plainly running the two programmes beside eachother has not resulted in problems yet, so I believe it has to deal with the way how the hw monitoring is read out once the function is called up.