Are you able to unpack the epub and see if the XHTML page for page 26 is somehow a duplicate of page 24?
I do not know how to do that. But 26 is fine? It's not a duplicate. The duplicate is between 25 and 26? Am I misunderstanding?
I'm guessing that you do know "how to do it."
First of all, is this a fixed layout or flowable EPUB? When I read your question, I was assuming that it was fixed layout, but we should be clear.
An EPUB is simply a zip file of web pages. If your EPUB is fixed layout, then each individual page will be a separate XHTML web page.
To view the contents of your EPUB, rename it from (example) JEFFERTOYA.epub to JEFFERTOYA.zip, and then unzip the file. When you look inside the unzipped file, you should see a single "mimetype" file, and then two folders - META-INF and OEBPS. Inside the OEBPS folder you'll find the XHTML page(s).
What I'm suggesting is that you figure out if, for whatever reason, there's a duplicate page in there (pages 24, 25 & 26) that's causing you're problem. If there's no duplicate, you haven't solved your problem, but you've eliminated a possibility...
Thanks for letting more know how to do that.
I followed your instructions and found that there is only one xhtml page.
That page, has all of the content and none of the content is duplicated.
Well, my next thought is to go back into your OEBPS folder and find the file labelled "toc.xhtml" - the table of contents.
When you look at that file in something like Dreamweaver, is does it appear that it's calling up your pages 24 and 25 (properly) and then your page 24 again, and then page 26, etc.????
After that, I'm out of long-distance suggestions...