Hello,
I think there is some sort of problem with ManagedProj4Projection.ConvertProj4ToPrj.
This code:
TextWriter t = new StreamWriter(ShapeFilePath.Substring(0, ShapeFilePath.LastIndexOf('.')) + ".prj");
t.WriteLine(ManagedProj4Projection.ConvertProj4ToPrj("+proj=tmerc +lat_0=39.66666666666666 +lon_0=1 +k=1 +x_0=200000 +y_0=300000 +ellps=intl +towgs84=-304.046,-60.576,103.64,0,0,0,0 +pm=lisbon +units=m +no_defs"));
t.Close();
Is giving the following prj string :
PROJCS["Transverse_Mercator",GEOGCS["GCS_International 1909 (Hayford)",DATUM["D_unknown",SPHEROID["intl",63783880,297]],PRIMEM["lisbon","-24,3561111111111"],UNIT["Degree",174532925199433]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin","3,96666666666667E+15"],PARAMETER["central_meridian",1],PARAMETER["scale_factor",1],PARAMETER["false_easting",200000],PARAMETER["false_northing",300000],UNIT["Meter",1]]
This is wrong, I guess the problem is related with the Culture being set to pt-PT.