DOCBOOK-APPS: Units in fo -> rtf using jfor

I would like to transform a fo file generated with the 1.53 XSL
stylesheets to rtf. When I use jfor I get the message:

jfor V0.7.1 - see http://www.jfor.org
Creating input and output objects...
Converting XSL:FO file 'novalis.fo' to RTF output 'novalis.rtf'...
jfor.INFO:jfor V0.7.1 - setting up conversion...
jfor.INFO:Parsing xsl:fo document...
org.xml.sax.SAXException: IOException in IBuilder:
org.jfor.jfor.converter.ValueConversionException:
 conversion factor not found for '%' units

Is there a XSL parameter to tell the XSLT not to use '%' units in the
output ? 

Thanks,
Ekkehard

-- 
Ekkehard G顤lach                    Tumringerstrasse 287
             D-79539 L顤rach