I've recently upgraded my Cybook Gen3 to the new firmware 2.0, that supports ePub format and not mobi. I diligently converted my books with calibre and sent them to the device.
Guess what I found out?
Title tags below h1 (h2, h3, h4) are not displayed by the Cybook. Not in epub files, nor in simple html files. Consequently, there isn't any kind of summary available on the reader. And the chapter names disappeared.
Here is an image of an epub file on my cybook, and
here an image of the same epub viewed by calibre.
What gives?
EDIT:
please notice, in the first image, that a little dash appears in the place where the chapter name should be.