I searched the forums, but didn't come across anyone else who reported this, I wondered if anyone else has experienced this.
I recently formatted a book and was informed that in the Nook reading app for both a desktop Mac and on an iPad, the cover image (which I manually inserted as a part of the book in addition to being a cover) and the title page (which I used an image for to obtain a specific appearance) were appearing twice.
I would have understood if it were the cover appearing twice, though that does not occur on the Nook itself, on the Nook app for Windows, or in any ePub reader that I've tried, but the title page image should never appear twice, as it is only included in the book once. I was able to replicate this behavior when I downloaded the application to a MacBook and opened the file. It is a file that has not yet been published and was manually copied to the device and added to the Nook software.
If anyone else has seen this happen, or knows whether it is a known bug, I would appreciate hearing from you. I searched the forums, but was only able to find year-old references to no images appearing on the Mac, rather than two. Perhaps I missed a relevant post?