... or something else?
The epub file from here:
http://www.smashwords.com/books/view/11428
Displays OK in Calibre as it is when you download it, but if you open it in Sigil and then save it, when you open it in Calibre again it will only show the cover page, not the story content.
Sigil is 0.2.0
Calibre is 0.6.54