Planning a flight from Elmsett to Turweston yesterday my paper printed route showed two dark shaded triangles, largely obscuring the underlying data. I experimented later and found: it happens on both my W10 desktop and my W7 laptop; it happens also using Microsoft "Print to PDF" as the destination (result attached); it only happened in portrait mode; deleting the waypoint at Little Shelford removed one of the triangles; removing the waypoint at Olney Town removed the other, so the print was now "correct"; it looks to me as if the vertices of the triangles are exactly on grid lines.
Alan