htmlhelp & draft image

Hi list,

is it possible to retain the draft image of my article in the generated 
chm file? The image is added via my customization layer

<xsl:param name="draft.watermark.image" select="'Graphic/draft.png'"/>

and shows up fine in the generated chunked html files that are used as 
input for the htmlhtlp compiler

<style type="text/css">
body { background-image: url('Graphic/draft.png');
        background-repeat: no-repeat;
        background-position: top left;
        /* The following properties make the watermark "fixed" on the 
page. */
        /* I think that's just a bit too distracting for the reader... */
        /* background-attachment: fixed; */
        /* background-position: center center; */
      }</style>

but disappears in the generated chm file. Is anybody else seeing this 
behaviour or am I missing something?

I'm using MS HtmlHelpWorkshop v4.74.8702.
On docbook side it's XSL stylesheets v1.66.1 and
$ xsltproc -V
Using libxml 20613, libxslt 10110-CVS940 and libexslt 808-CVS940
xsltproc was compiled against libxml 20613, libxslt 10110 and libexslt 808
libxslt 10110 was compiled against libxml 20613
libexslt 808 was compiled against libxml 20613

Thanks for your help,
Patrick