Rounded corner in xy package and ellipse shape

This question very hard for me. xy package have also the shapes, circle with [o], or other forms using this table:

    documentclass[a4paper,12pt]{article}
    usepackage[all]{xy}
    begin{document}
    xymatrix{
*++++[F-:<5pt>]{txt{Highlabel}}ar[dr] & &
& *++++[F-:<5pt>]{txt{Second text}}ar[r] & 
}
    end{document}

I have tried a code but….to increase the long text into the shape I must to add severals +. My output is:

where I see in the rounded corner (see the red square) a strange closure. Is it normal? But if I would to have an ellipse, is it possible with xy package, option xymatrix?