OCC STEP File error when loading in solidworks or pro/e

Hello everybody,

I have some problems when I try to to save the following shape into a step file in OCC:

gp_Pnt pnt_pos(0, 0, 0);
gp_Dir dir_ric(1, 0, 0);
gp_Dir dir_nor(1, 1, 1);
gp_Dir dir_stu(0, 1, 0);
Standard_Real radius 100;
Standard_Real radius_stutzen 10;
Standard_Real laenge 200;
Standard_Real laenge_stutzen 50;

gp_Ax2 ax2_lok(pnt_pos, dir_ric.Reversed(), dir_stu);
gp_Ax1 axe_ric(pnt_pos, dir_ric);
Handle(Geom_RectangularTrimmedSurface) innenwand_1 = GC_MakeTrimmedCylinder(axe_ric, radius, laenge);
TopoDS_Face iwand_zyl_face = BRepBuilderAPI_MakeFace(innenwand_1);
TopoDS_Shape iwand_zyl = iwand_zyl_face;

gp_Vec vec_stu(dir_ric);
vec_stu.Scale( laenge / 2.);
gp_Ax1 axe_stu(pnt_pos.Translated(vec_stu), ax2_lok.XDirection());
Handle(Geom_RectangularTrimmedSurface) innenwand_2 = GC_MakeTrimmedCylinder(axe_stu, radius_stutzen, radius + laenge_stutzen);
TopoDS_Face iwand_stu_face = BRepBuilderAPI_MakeFace(innenwand_2);
TopoDS_Shape iwand_stu = iwand_stu_face;

gp_Ax2 ax2_zyl = gp_Ax2(pnt_pos, dir_ric);
TopoDS_Solid vollzyl = BRepPrimAPI_MakeCylinder(ax2_zyl, radius, laenge);

gp_Ax2 ax2_stu = gp_Ax2(pnt_pos.Translated(vec_stu), ax2_lok.XDirection());
TopoDS_Solid vollstu = BRepPrimAPI_MakeCylinder(ax2_stu, radius_stutzen, radius + laenge_stutzen);

TopoDS_Shape zyl = BRepAlgoAPI_Cut(iwand_zyl, vollstu);

TopoDS_Compound zylinder;
BRep_Builder aBuilder;
aBuilder.MakeCompound (zylinder);
aBuilder.Add (zylinder, zyl);
aBuilder.Add (zylinder, stu);

// The zylinder compound the is written to step via:

STEPControl_Writer writer;
writer.Transfer( zylinder , STEPControl_ShellBasedSurfaceModel);
writer.Write("Output.stp");

The shape is are just two orthogonal pipes that are melted together. The step export works just fine. When I open the Step File in GMSH, which is based on the OCC library, there are no problems opening the file. But when I try to open the step file in pro/e or solidworks there are some problems. One of the two pipes are not opened.

Thanks for helping me in advance!

Sammy