PDFsharp & MigraDoc Foundation

Good morning to every one, I'm using teh nuget pdfsharp library 1.51.5185-beta into a c#-wpf project. i have found a problem to draw two easy arcs. In detail here the two arc added to the var path = new XGraphicPath():

path.AddArc(new XPoint(45,25), new XPoint(5,25), new XSize(20, 20), 0, false, true);
path.AddArc(new XPoint(5,25), new XPoint(45,25), new XSize(20, 20), 0, false, true);

The right result should be a perfect circle (see right circle picture attached) but the result i have obtained is two arcs on top of each other. (see wrong circle picture attached)

Can some one help me about it? is it a bug or am i missing something? It seems a problem just if the start/end points are aligned to X or Y axes.

Thanks a lot for your time.