bug in svg circle

hello,

i made a simple logo in svg with inkscape, representing the rounded "E"
of the french education ministery (see for example
http://www.education.gouv.fr/_gfx/ban_haut_gauche.gif).

this logo is viewable here:  http://www.ac-nice.fr/ia06/logos/e-logo.svg
or, in a bitmap format, here http://www.ac-nice.fr/ia06/logos/e-logo.png

when i see this logo with adobe SVG reader (or, of course, inkscape), 
all is fine. However, with amaya, the circle is not filled, and the "E" 
letter is not surrounded by cyan border.