@jbmangan: I did try the error version and I was able to see the problem. As @theducks said, it is almost definitely related to the table that wraps that section of text. I know it is recommended to avoid tables in epubs, but, that is usually about the multiple columns being to wide.
Sending the book to the device as a kepub using the KoboTouchExtended driver appears to work correctly. I can see the parchment background for the section where the text was missing. And I there is no obvious missing text.
The problem you saw with the "Part" page is actually working as designed. The code for these pages are:
Code:
<div class="full"><a href="../Text/Contents.xhtml#p1" class="calibre1"><img alt="Part One" src="../Images/part_one.PNG" class="calibre3"/></a></div>
That basically fills the screen with a link to the comments page. Tapping anywhere on it will activate the link. You will need to swipe on the page to turn it.