<xsl:include> using relative paths and Saxon 8

Hi,

Sorry if this is a subject that's been answered before but I've worn
myself out searching.

In brief:

1) I've just started using Saxon 8.
2) I'm using XSLT stylesheets by loading through a URL (i.e. not File) .
3) I am including another XSLT using a RELATIVE path
	<xsl:include href="Common.xsl"/>
4) It goes bang - can't find the Common.xsl since it's looking the
   the "wrong" place.
5) If I give the<xsl:include> and absolute URL it works.
6) All this was working fine before I switched to reading my XSLT via
   a URL.

I want to read the XSLT via URL because my app is invoked via Web Start
and I want to download the stylesheets from the server.

Any pointers?  I must be doing something stupid here.

Thanks all
Chris