[MacEachaidh]

I'm fairly new to epub formatting, and so far my issues have been few, but I've hit a speed-hump that's befuddling me, and I'd appreciate any suggestions as to how to resolve it.

I've created an epub that functions perfectly, *except* at one specific point, where an uncoded pagebreak occurs — not in ADE, not in the latest version of Sigil, but in my eReader (a Kobo Touch with 2.5.1 firmware). And when I page through the book on my Kobo, accessing that one page is always extremely slow, when the rest of the book isn't.

It behaves as if there's some hidden code at that point. Is that even possible? If I change the font size in the Kobo, so that the pagination falls differently, then the page still breaks at that same point — a paragraph break at the end of a five-line paragraph — every time. I've made an edited version of the epub, containing only two paragraphs — the one before the break and the one following — and it still reads with a page break at that point.

I've visually checked the code in Sigil: I can see nothing unexpected. The coding is very simple there: only a paragraph style, with no inherited values or character codes. I've validated the CSS in the W3C validation page, and it passed with no issues; ditto the epub itsef in Sigil's inbuilt FlightCrew, with no errors found. The fault could conceivably be with Kobo's firmware, but there must be something at that point to trigger it, since it happens nowhere else in the book.

I'm stumped. Any suggestions, please?