[UPDATE: January 2016: Amazon now allow for publishers to embed their book covers inside the file before upload to KDP; if you are using a jpeg title page, I would advise that you embed your cover. This way Amazon’s system will not mistake your title page for the cover. Note also that embedding your cover requires specific code. See the KDP guide for more information.]
A client recently uploaded to Kindle Direct Publishing a new book that I designed for him that had a jpeg image for its title page—a trend that gives the title page a much more polished appearance and allows for the use of custom fonts—and we discovered an unfortunate bug: Amazon’s convertor breaks the NCX TOC, relinking the title page to the cover entry.
The file included both an HTML TOC and an NCX TOC; both contained the entry “Title” that linked to the title page jpeg. Nowhere in the code, including nowhere in the content.opf, was there any code indicating the inclusion of a cover in the file. This is because I know that Amazon do not want the cover embedded in an ebook file, but want the cover uploaded separately.
When you upload your cover and book file, Amazon adds a cover entry to the top of your NCX file; if you don’t have an NCX file (if you uploaded a Word doc or HTML file, for example), then the convertor creates an NCX file and creates entries for only those items bookmarked—your beginning, your HTML TOC—and adds the cover entry.
Because Amazon do not want the cover embedded, their system has been programmed to look for anything that resembles a cover and to overwrite it with the cover you upload. The unfortunate result is that if you have a jpeg title page, Amazon’s system can’t tell the difference and treats is as a wrongly embedded cover. Thus, Amazon breaks the link between the “Title” entry and the jpeg in the NCX TOC and relinks “Title” to the cover added upon upload. Thus you end up with an NCX TOC with both “Cover” and “Title” linked to the cover. Thankfully, however, the title page jpeg remains inside the book and is otherwise untouched.
The HTML TOC code is unchanged, so the link from “Title” to the title page remains intact there. When the user clicks on the Go to Table of Contents in their Kindle device or app, it links to the HTML TOC so the problem will not appear. The problem only appears in Kindle apps that allow the user to click on the optional NCX TOC.
My client also discovered ours was not an isolated incident: he had bought Ian McEwan’s Atonement, which also has a jpeg title page, and the problem is present in that file, too:
I informed Amazon of the issue and recently heard back from them that they were able to replicate the problem and are looking into a fix. I have asked them to let me know if and when this happens so my client may upload a replacement file (that will not then be broken) and I can inform my readers. Will see what transpires.