Thank you again for your help. I am new to Calibre conversion having always used BookDesigner and lrfs so I am learning as I go along. For some reason I had heuristic option set on but that caused another problem with another book which has been corrected when I switched it off.
Now I reconverted this book but the same happened but the break was at a different place a few lines earlier - 'Only she and Calaban' then split to the next page. I don't think it is a particular sentence that is causing the page throw, it always appears at exactly the same place on the screen - half way down. After the few lines are displayed on the next screen there is a correct page throw to the next chapter.
This is the html / css from the latest conversion without the heuristic option:-
---------------------- first html
think of my reasons for doing so," she said, "I must ask you again to leave, by the back way. Our next appointment is in three days, is it not?"</p><p class="calibre4"> "Yes," said Prospero. "We have several other appointments that will take up the intervening time."</p><p class="calibre4"> "Fine then. Return in three days, in the afternoon, and we will conclude our business."</p><p class="calibre4"> Caliban nodded his head towards her, in what was almost a bow. "Very well," he said in a most courteous tone. "We will see you at that time."</p><p class="calibre4"> Prospero took no interest in courtesy. He simply turned, opened the door, and left the room, leaving all the farewells to his companion. Caliban had to hurry just to keep up with him.</p><p class="calibre4"> Fredda watched them go, and found herself once again wondering about Prospero. She did not understand what went on behind those glowing eyes. There was something not quite right about a robot that—that secretive. She shook her head as she crossed the room. Not much point in worrying about it now. She sealed the door shut behind them and scrambled the keypad. Only she and Caliban and Prospero knew the door's keypad combination.</p></div><div class="s1"><p class="calibre4"> And there were times she thought seriously about taking at least one name off that list.</p></div></div><div class="calibre1"><div class="s"><div class="calibre3" id="calibre_pb_3"></div>
</div></div></div></body></html>
---------------------- next html
<?xml version='1.0' encoding='utf-8'?>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta name="generator" content="http://calibre-ebook.com"/>
<title>Utopia</title>
<meta name="author" content="Roger MacBride Allen"/>
<meta name="creation-time" content="2019-2-23"/>
<meta name="revision-time" content="2022-9-8"/>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<link href="stylesheet.css" rel="stylesheet" type="text/css"/>
<link href="page_styles.css" rel="stylesheet" type="text/css"/>
</head>
<body class="calibre">
<div class="calibre1">
<div class="calibre1">
<div class="s">
<h1 id="calibre_toc_4" class="calibre2">Chapter 2</h1></div><div class="s1"><p class="calibre4"> Caliban followed Prospero down the tunnel. It ran for about a hundred meters, and deposited them at the base of a ravine that was otherwise quite inaccessible to the house. Their aircar was hidden there.</p><p class="calibre4"> "I would like to know what all that was about," Caliban said as they emerged from the tunnel into the cool of the evening.</p><p class="calibre4"> "I spoke the truth," Prospero said coolly. "It was in part merely a test to see how she would react to such an accusation. Surely you would agree it is worth knowing if she is capable of betraying us." Prospero climbed into the pilot's station.</p><p class="calibre4"> Caliban followed, climbing into the forward
-----------------------------------
page style css
@page {
margin-bottom: 0;
margin-top: 0
}
@font-face {
font-family: "Book Antiqua";
panose-1: 2 4 6 2 5 3 5 3 3 4;
src: url(fonts/Book-Antiqua.ttf)
}
@font-face {
font-family: "Book Antiqua";
panose-1: 2 4 7 2 5 3 5 3 3 4;
src: url(fonts/Book-Antiqua-Bold.ttf);
font-weight: bold
}
@font-face {
font-family: "Book Antiqua";
panose-1: 2 4 5 2 5 3 5 10 3 4;
src: url(fonts/Book-Antiqua-Italic.ttf);
font-style: italic
}
@font-face {
font-family: "Book Antiqua";
panose-1: 2 4 7 2 6 3 5 10 2 4;
src: url(fonts/Book-Antiqua-Bold-Italic.ttf);
font-style: italic;
font-weight: bold
}
----------------------
stylesheet css
.calibre {
display: block;
font-family: "Book Antiqua", serif;
font-size: 1.08333em;
line-height: 1.2;
padding-left: 0;
padding-right: 0;
text-align: left;
margin: 0 5pt
}
.calibre1 {
border-bottom: 0;
border-top: 0;
display: block;
margin-bottom: 0;
margin-top: 0;
padding-bottom: 0;
padding-top: 0;
text-indent: 1.5em
}
.calibre2 {
display: block;
font-size: 1em;
font-weight: bold;
line-height: 1.2;
margin: 0.67em 0
}
.calibre3 {
border-bottom: 0;
border-top: 0;
display: block;
margin-bottom: 0;
margin-top: 0;
padding-bottom: 0;
padding-top: 0;
text-indent: 1.5em
}
.calibre4 {
border-bottom: 0;
border-top: 0;
display: block;
padding-bottom: 0;
padding-top: 0;
text-indent: 1.5em;
margin: 0
}
.none {
font-style: italic;
font-variant: normal;
font-weight: normal;
text-decoration: none
}
.s {
border-bottom: 0;
border-top: 0;
display: block;
font-weight: bold;
margin-bottom: 0;
margin-top: 0;
text-align: center;
padding: 0
}
.s1 {
border-bottom: 0;
border-top: 0;
display: block;
margin-bottom: 0;
margin-top: 0;
text-align: left;
text-indent: 1.5em;
padding: 0
}
--------------------------
I am sorry to perservere with this but I have converted all my books using Calibre and, apart from losing real page numbers, have been very happy with epubs but this is puzzling. I have a prs-300 and the same thing happens with that.
It would be really nice to know what is causing this and not put it down to one of life's little mysteries.