Дим, я проверил с FF, с IE7 и с линуксовым xsltproc - все три программы одинаково отказались работать с таким xlmns.
Пример длинный...
<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
<xsl:output method="html"/>
<xsl:template match="/FictionBook">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<link rel="stylesheet" type="text/css" href="fb2.css"/>
<title><xsl:value-of select="description/title-info/book-title"/></title>
</head>
<body>
<div id="title">
<div class="title"><xsl:value-of select="description/title-info/book-title"/></div>
<div class="author">
<xsl:value-of select="description/title-info/author/last-name"/>
<xsl:text> </xsl:text>
<xsl:value-of select="description/title-info/author/first-name"/>
<xsl:text> </xsl:text>
<xsl:value-of select="description/title-info/author/middle-name"/>
</div>
<div class="isbn">ISBN: <xsl:value-of select="description/publish-info/isbn"/></div>
</div>
<div id="contents">
<xsl:for-each select="body/section">
<a href="#section{position()}" class="title"><xsl:value-of select="./title/p"/></a>
</xsl:for-each>
</div>
<div id="body">
<xsl:apply-templates select="body"/>
</div>
</body>
</html>
</xsl:template>
<xsl:template match="body">
<xsl:for-each select="section">
<div id="section{position()}" class="section">
<xsl:apply-templates/>
</div>
</xsl:for-each>
</xsl:template>
<xsl:template match="section/title">
<div class="title"><xsl:apply-templates/></div>
</xsl:template>
<xsl:template match="title/p">
<div><xsl:value-of select="."/></div>
</xsl:template>
<xsl:template match="section/subtitle">
<div class="subtitle"><xsl:apply-templates/></div>
</xsl:template>
<xsl:template match="subtitle/p">
<div><xsl:value-of select="."/></div>
</xsl:template>
<xsl:template match="p">
<xsl:choose>
<xsl:when test="name(child::*) = 'emphasis'">
<p class="emphasis"><xsl:value-of select="./emphasis"/></p>
</xsl:when>
<xsl:otherwise>
<p><xsl:apply-templates/></p>
</xsl:otherwise>
</xsl:choose>
</xsl:template>
</xsl:stylesheet>
, то все равно не работает. А вот без указания имени тега - работает:
