Undocument 'feature' of PixelOffsetMode.Half :))

[T]

When I call graphics.DrawRectangle(Pens.Black, 100, 100, 10, 10) the
top left pixel is not painted if PixelOffsetMode is set to
PixelOffstMode.Half. Why?

Looks like a serious bug to me. PixelOffsetMode.Half is supposed to
be
more accurate than the default mode so why this?

protected override void OnPaint(PaintEventArgs e)
{
Graphics g = e.Graphics;
g.PixelOffsetMode = PixelOffsetMode.Half;
g.DrawRectangle(Pens.Black, 100, 100, 10, 10);
}