venta

I apologise for the volley of XML/HTML/other baleful pointy-bracket-related questions on here of late. Me and the pointy brackets are not friends.

So, if anyone knows anything about Docbook XML, I'd like to know why the following...
<!DOCTYPE article PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">

<article>
<articleinfo>
<mediaobject>
<imageobject>
<imagedata fileref="my_graphic.png" format="PNG"/>
</imageobject>
</mediaobject>
<title>An Exciting Document</title>
<copyright><year>2007</year>
<holder>Venta</holder>
</copyright>
</articleinfo>

... rest of article...

generates an article which has no graphics at all in the header. The generated html doesn't have any reference to my graphic in it at all.

The DocBook DTD says that mediaobject can be a child of articleinfo, and the XML is perfectly valid according to xmllint (which validates it against the DTD).

I'm assuming that the DocBook stylesheets must somehow be failing to generate any <img> tags, but the DocBook stylesheet set is so large and behemothlike that I'm being a bit daunted at the prospect of how I'm going to find the relevant clause in it. I don't speak anything but very basic XSL.

So, does anyone have any idea (a) what the problem might be, or (b) how I might go about tracking it down. A means of determining which clauses had been invoked from the stylesheets (like a debugging parser, maybe) would be useful if such a thing exists.