Barcode with fop0.9

Question

Hi, i am using the fop-0.95,barcode4j.jar and barcode4j-fop-ext.jar to generate the barcode. My barcode generation xsl code is

<fo:instream-foreign-object> <xsl:variable name="BARCODE">
  <xsl:value-of select="BARCODE"/></xsl:variable>

    <xsl:variable name="BARCODE-CFG">
             <barcode>
                    <code128>
                     <human-readable>none</human-readable>
                    <height>5mm</height>
                          <quiet-zone enabled="false"/>
                        </code128>
                      </barcode>
       </xsl:variable>
     <xsl:copy-of select="barcode:generate($BARCODE-CFG,$BARCODE)"/></fo:instream-foreign-object></xsl:variable>

And i am getting the following error

SEVERE: javax.xml.transform.TransformerException: java.lang.NoSuchMethodExceptio n: For extension function, could not find method org.apache.xml.dtm.ref.DTMNodeI terator.generate([ExpressionContext,] #NODESET). Oct 29, 2009 11:44:08 AM org.apache.fop.cli.Main startFOP SEVERE: Exception javax.xml.transform.TransformerException: org.apache.fop.fo.ValidationException: Error(Unknown location): fo:instream-foreign-object is missing child elements.

Required Content Model: one (1) non-XSL namespace child at org.apache.fop.cli.InputHandler.transformTo(InputHandler.java:217) at org.apache.fop.cli.InputHandler.renderTo(InputHandler.java:125) at org.apache.fop.cli.Main.startFOP(Main.java:166) at org.apache.fop.cli.Main.main(Main.java:197)

Please tell me what is the problem