I'm having this problem myself - my page breaks work in every browser but Chrome - and was able to isolate it down to the page-break-after element being inside a table cell. (Old, inherited templates in the CMS.)
Apparently Chrome doesn't honor the page-break-before or page-break-after properties inside table cells, so this modified version of Phil's example puts the second and third headline on the same page:
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="content-type" content="text/html;charset=UTF-8" />
<title>Paginated HTML</title>
<style type="text/css" media="print">
div.page
{
page-break-after: always;
page-break-inside: avoid;
}
</style>
</head>
<body>
<div class="page">
<h1>This is Page 1</h1>
</div>
<table>
<tr>
<td>
<div class="page">
<h1>This is Page 2</h1>
</div>
<div class="page">
<h1>This is, sadly, still Page 2</h1>
</div>
</td>
</tr>
</table>
</body>
</html>
Chrome's implementation is (dubiously) allowed given the CSS specification - you can see more here: http://www.google.com/support/forum/p/Chrome/thread?tid=32f9d9629d6f6789&hl=en