Global parameters with UTF-8 characters and ???s

I am having problems with global parameters which have UTF-8 characters
in them.  They show up as question marks when I use their values in the
output (e.g. <xsl:value-of select="$global-parameter"/>).

I am using JAXP (with Xalan 2.6 as the underlying XSLT engine) from a
JSP page to generate HTML.

My JSP page has the following setting for UTF-8:

<%@ page contentType="text/html;charset=UTF-8" language="java" %>

My XSLT stylesheet has the following XML declaration:

<?xml version="1.0" encoding="UTF-8"?>

And the stylesheet also has the following output element:

<xsl:output method="html" indent="yes" encoding="UTF-8"/>

I am using the following Java code to set the global parameters:

transformer.setParameter(key, resourceBundle.getString(key));

So I think I am setting everything up properly for UTF-8.  Is there
anything I am doing wrong that is causing these characters to be shown
as question marks?

Thanks in advance for any help.

Regards,
Dave