DOCBOOK-APPS: Problems with <imageobject>...

Hi,

I wrote the following statements:

<figure id="my-id">
  <title>My figure</title>
  <mediaobject>
    <imageobject>
      <imagedata fileref="myImage.png" format="PNG"/>
    </imageobject>
    <textobject>
      <phrase>My phrase</phrase>
    </textobject>
  </mediaobject>
</figure>

When I'm attempting to generate HTML output
with xsltproc, I always get the following message:

Error Undefined namespace prefix
xmlXPathCompiledEval: evaluation failed

I'm using the DocBook stylesheets 1.57.

Has anybody ever seen something like this?

-- 
Giuseppe Greco
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