Originally Posted by JeanneLaska
That sounds very similar to a problem I've had.
The problem appeared on a Kobo reader: not only were there arbitrary page numbers (following a set number of words rather than the layout chosen by the Kobo's owner), but those page numbers were literally on the text, as GraciousMe reported.
They're not exactly arbitrary page numbers, they're page numbers based on an ADE definition of a "page" in a reflowable epub ebook being 1024 btyes. (Everyone uses a different font, font size, margin, etc - we have to agree on what constitutes a "page" somehow.)
You can simply turn their display off in page 2 of the Reading Settings, "Page Numbers In Margins". Alternatively, if you prefer to see them, you could set your margin a little wider.