I am terribly sorry but the two facts are not true, therefore they are not facts.
I have seen collision points around my model, but the experiment can not be repeated.
On the other hand it is true, that the edge of propeller is just touching the ground, but it might be because the whole model is above the ground, and in this case even the 7. par file is wrong but I dont know why.
I will check.
Regards
Laszlo