I think this is a fix at:
http://www.biglist.com/lists/xsl-list/archives/200108/msg00541.html

However I don't understand it.
and I presume this is off topic.

---
Alex.

Alex wrote:

If I add to the XSL:
<xsl:output method="html" encoding="ISO-8859-1" />
It does not make any difference to the output.
The problem is happening further down the pipeline.

Possibly in the parser?

If I use Xalan to parse it I get:
<META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">

If I use MSXML to parse it I get
<META http-equiv="Content-Type" content="text/html; charset=UTF-16">

I think that I need to change response.charset

I wonder if this is what has caused the erroneous ? marks.

Again:

If this is served from IIS, you almost certainly have XSLT/ASP bug #1: sending the transformation result as a string to the response object, instead of using transformNodeToObject.

Regards, Julian