HTML Page to EPUB Named Anchor Problem

I am trying to convert an HTML page to EPUB using Calibre version 1.5.
The conversion works but all of the named anchors in the ebook Table of Contents link back to the web site.
How do I tell Calibre to convert the named anchors to go to the proper ebook page?
This is the HTML page I am trying to convert, http://www.w3.org/TR/html5/single-page.html.
TIA.