Commented Issue: Polygon ShapeFile - 5 categories, applied single colour – strange image on screen... [21832]

Hello!
 
This time I did following:
 
Created memory polygon shape file.
 
Added decimal filed, added number of polygons with attribute values, please note: all polygons are squares. Also there are no gaps between squares.
 
After that I created 5 categories with the same colour (outlines are not shown) and applied expression (see the code below).
As a result – image with very strange artefacts on a screen
I saved this shape file on a harddrive and did the same kind of things in the latest Mapwindow application – the same result!
 
All screenshots and shape file you can find in the attached archive.
 
Regards,
Igor.
 
P.S. Code:
SMSScalarSet st = ramp.Styler as SMSScalarSet;
shapefile.Categories.Clear();
shapefile.Categories.Key = "";
shapefile.DefaultDrawingOptions.DrawingMode = MapWinGIS.tkVectorDrawingMode.vdmGDIMixed;
shapefile.DefaultDrawingOptions.FillColor =ColorToUInt(Coor.Blue);
RGBpack.RGB(ramp.Set.SingleColour);
shapefile.DefaultDrawingOptions.FillTransparency =255;
shapefile.DefaultDrawingOptions.FillType = MapWinGIS.tkFillType.ftStandard;
shapefile.DefaultDrawingOptions.FillVisible = true;
shapefile.DefaultDrawingOptions.LineVisible = false;
shapefile.DefaultDrawingOptions.LineWidth = 1;
shapefile.DefaultDrawingOptions.VerticesVisible = false;
shapefile.MinDrawingSize = 1;
shapefile.ApplyCategories();
Comments: ** Comment from web user: sleschinski **

I've just committed a fix: GlobalSettings.PixelOffsetMode property. With pomHighQuality the artifacts disappear.