DOCBOOK-APPS: Bordernotes

Hi list,
Last week I asked whether anybody had done something like notes at the
border of the text, but got not replies. Maybe I didn't express myself
clearly enough? Anyway, here it is.
I have attached an example PDF and the corresponding XML and XSLT.  
I use a format of 
<xsl:param name="page.width">240mm</xsl:param>
<xsl:param name="page.height">190mm</xsl:param> 
<xsl:param name="page.margin.outer">4cm</xsl:param>
<xsl:param name="page.margin.inner">2cm</xsl:param>
for my texts, so that I have a lot of space to use and currently the
values for the bordernotes are hardcoded.

This might not work with all texts. I encountered "nulls" from FOP when
I had very long paragraphs and a lot of footnotes. It seems that at a
certain point FOP is no more able to calculate the wrapping of the text.

Stephan