I just converted the book in question to mobi and sent it to my Kindle, and it works fine, no skipping at all. I don't have any epub reader on my computer, other than calibre, and it reads fine in that too. So I still don't know what the deal is.
I have learned that when it skips back from 144 to 92, if I hit the page back button, it goes back to 144, then page forward goes back to 92 again, and so on and so on.
And since I don't have wi-fi in my house, that's not something that really ever gets turned on, so if that has to be turned on to fix it, I'll have to go to mickey d's or something.
And again, this has happened on at least 3 or 4 books- 3 fanfic books created with either Flagg or the ffic downloader in calibre, and one regularly pubbed book.