DOCBOOK-APPS: sub/superscript in Apache's FOP 0.20.4 does not work?

[Egon Willighagen <egonw at sci dot kun dot nl>]

Hi all,

I am writing an article in DocBook and using XML->FOP->PDF
with the stylesheets (1.52.1 and xsltproc) and Apache's FOP 0.20.4 and am 
having problems with super and subscript: they are not superscripted in PDF.

I have this DocBook XML code:

        <para>
                In recent years these ideas have been part of the open-source
		... <!-- text removed -->
                bugs are shallow", as Eric Raymond put it in his widely
                recognized essay "The Cathedral and the Bazaar"
		<superscript>1</superscript>, in
                which he analyses the mechanisms and principles of the open
                source movement.
        </para>


The stylesheets generate this FOP code:

<fo:block space-before.optimum="1em" space-before.minimum="0.8em" 
space-before.maximum="1.2em">
                In recent years these ideas have been part of the open-source
		... <!-- text removed -->
                bugs are shallow&quot;, as Eric Raymond put it in his widely
                recognized essay &quot;The Cathedral and the Bazaar&quot; 
<fo:inline baseline-shift="super">1</fo:inline>, in
                which he analyses the mechanisms and principles of the open
                source movement.
        </fo:block>

Apache's FOP does not produce a PDF with this "1" superscript.
Similar problems with subscript...

Is this 'normal' behaviour? Do others get PDFs with proper sub/superscripts?
What should I do to get things superscripted in PDF?

Any ideas would be enormously welcome.

kind regards,

Egon Willighagen