[Therion] svg black parts

I have an issue with black-parts in the embedded svg in extensible HTML export. The problem is separated in the attachment. There are some invisible borders with area objects. One of them is shown in black. The pdf export looks fine. Is this a svg export bug or a symbol problem. Have anyone an idea to bypass this, with the same symbol? If the order of the objects will be changed, the black-part is then a another of the area objects. Thanks, /d