xsl:include problems

We're using MSXML4 and I'm trying to get xsl:include to work but I'm having
trouble.  I created file "replace_string.xsl" that contains this:

<?xml version="1.0" encoding="UTF-8" ?>
<stylesheet version="1.0" xmlns="http://www.w3.org/1999/XSL/Transform">

<xsl:template name="replace-string">
	<xsl:param name="text"/>
	<xsl:param name="replace"/>
	<xsl:param name="with"/>

	<xsl:choose>
		<xsl:when test="contains($text,$replace)">
			<xsl:value-of select="substring-before($text,$replace)"/>
			<xsl:value-of select="$with"/>
			<xsl:call-template name="replace-string">
				<xsl:with-param name="text" select="substring-after($text,$replace)"/>
				<xsl:with-param name="replace" select="$replace"/>
				<xsl:with-param name="with" select="$with"/>
			</xsl:call-template>
		</xsl:when>
		<xsl:otherwise>
			<xsl:value-of select="$text"/>
		</xsl:otherwise>
	</xsl:choose>

</xsl:template>

</stylesheet>

*---------------------------------------------------------------------

Then in another style sheet where I want to "include" that template I use this
as a top-level element:

<xsl:include href="replace_string.xsl" />

Now "replace_string.xsl" is in the same application directory as the ASP page
rendering the page, and the xsl style sheet being rendered is in the same
directory.  What happens is that I get a blank page in the browser when that
page is rendered.  If I comment out the xsl:include then the page renders ok.
I've tried putting replace_string.xsl in the document root but that didn't
help.  I'm sure there is something stupid that I'm (not) doing - please tell
me what the problem is.

TIA.

Hardy Merrill