I read on a close post that surface can generate meshing problem.
I know this point, but with the part st3, which has exactly the same constructions with surfaces, meshing is working good - except the fact that the sweep2 is disappearing when entering in SimulX : I have to check this sweep in the solid bodies list, at each simul running ....one more bug to add to the list of SW !!!!
----2 bugs, in fact, since all the surfaces are turned from hide to show, when exit from SimulX !!!!!