[xsl] Inserting XML into stylesheet using copy-of

[Rob Belics <rob_belics@xxxxxxxxxxx>]

When I use a local file, I can insert an XML file into my xslt
stylesheet doing this:
<xsl:copy-of select="document('s1.xml')"/>

So I put s1.xml on my personal site:
<xsl:copy-of select="document('http://mysite.com/xml/s1.xml')"/>
but it fails with "XML Parsing Error: no element found"

s1.xml only contains <here>hello</here> and I can access it via a
browser. What am I doing wrong?