Comment 8 for bug 256624

cc:ing Ben Newman who said he could help look into this. Ben, in this case we end up creating two nsSubDocumentFrame's (and other frames too) for a single DOM node, the construction of the frames happens off of notifications from the content sink (ContentAppended() most likely, in either nsHTMLContentSink or nsContentSink). We should only ever get one notification for any given DOM node being inserted into the DOM tree, but in this case we most likely fire two of them, and thus end up with the duplicated frames etc.

Feel free to take this bug if you'll be able to get to it before Jonas does...