[Rand Brittain]

I've been cleaning up some EPUBs for use on my Reader, and I've hit a weird issue with my CSS. I've inserted a page break after my chapter headings, and the space shows up fine in Calibre's reader, but on my PRS-350 and on my Bookeen Opus, the break does not appear and there is no space between the heading and the first paragraph.

This is the first part of the chapter:

<h3 id="heading_id_4"><a id="chapter_1"></a>1: <span class="italic">Damp Dynamite</span></h3>

  <div class="break">
    <br />
  </div>

  <p>The story of the little man...</p>

And this is my stylesheet:

@page {
	margin-top: 0.25em;
	margin-bottom: 0.25em;
}

body {
	display: block;
	text-align: justify;
}

p {
	text-indent: 2em;
	margin-top: 0;
	margin-bottom: 0.25em;
}

h1, h2, h3, h4, h5 {
	text-align: center;
	text-indent: 0;
}

p.missive {
	margin-left: 1em;
	margin-right: 1em;
	text-indent: 0em;
}

p.missive-indent {
	margin-left: 1em;
	margin-right: 1em;
	text-indent: 2em;
}

.center {
	text-align: center;
}

.italic {
	font-style: italic;
}

.bold {
	font-weight: bold;
}

.small-caps {
	font-variant: small-caps;
	}

.right {
	text-align: right;
	}

blockquote {
	margin-left: 1em;
	margin-right: 1em;
	text-indent: 0;
	}

.break {
	margin-bottom: 1em;
	}

Any idea of what might be causing this problem?