Glossary format in PDF

In my docbook book the glossary is formatted in block form using

  <xsl:param name="glossary.as.blocks"          select="1"/>

in my customization layer. In the PDF output the glossterms are, however, 
closer to the glossdefs of the previous entry than to it's own definition. 
Can I customize the distance between term and definition (the HTML output 
is fine)?

Thanks,
Ekkehard