Exception with 'double.sided' set to 1 for PDF output

When trying to generate PDF with <xsl:param name="double.sided" select="1" /> generated exception.
The same works with <xsl:param name="double.sided" select="0" />

FOP version : 0.94
DocBook XSL : 1.73.2

=====
D:\wrk\BookTest>fop-0.94\fop.bat -xml input\test\index.xml -xsl custom\test-header.xsl -pdf output\test\test.pdf
Oct 1, 2007 4:58:56 PM org.apache.fop.cli.InputHandler warning
WARNING: javax.xml.transform.TransformerException: Note: namesp. cut : stripped namespace before processing           Book Title
Oct 1, 2007 4:58:56 PM org.apache.fop.cli.InputHandler warning
WARNING: javax.xml.transform.TransformerException: Note: namesp. cut : processing stripped document                   Book Title
Oct 1, 2007 4:58:56 PM org.apache.fop.cli.InputHandler warning
WARNING: javax.xml.transform.TransformerException: Making portrait pages on USletter paper (8.5inx11in)
Oct 1, 2007 4:58:57 PM org.apache.fop.fo.FOTreeBuilder$MainFOHandler endElement
WARNING: Mismatch: root (http://www.w3.org/1999/XSL/Format) vs. page-sequence (http://www.w3.org/1999/XSL/Format)
Oct 1, 2007 4:58:57 PM org.apache.fop.fo.FOTreeBuilder fatalError
SEVERE: javax.xml.transform.TransformerException: java.lang.IllegalStateException: endElement() called for fo:root where
 there is no current element.
Oct 1, 2007 4:58:57 PM org.apache.fop.cli.Main startFOP
SEVERE: Exception
javax.xml.transform.TransformerException: java.lang.IllegalStateException: endElement() called for fo:root where there i
s no current element.
        at org.apache.fop.cli.InputHandler.transformTo(InputHandler.java:168)
        at org.apache.fop.cli.InputHandler.renderTo(InputHandler.java:115)
        at org.apache.fop.cli.Main.startFOP(Main.java:166)
        at org.apache.fop.cli.Main.main(Main.java:197)

---------

; SystemID: file:/D:/wrk/BookTest/docbook-xsl-1.73.2/fo/docbook.xsl; Line#: 223; Column#: 59
javax.xml.transform.TransformerException: java.lang.IllegalStateException: endElement() called for fo:root where there i
s no current element.
        at org.apache.xalan.transformer.TransformerImpl.executeChildTemplates(TransformerImpl.java:2416)
        at org.apache.xalan.templates.ElemIf.execute(ElemIf.java:160)
        at org.apache.xalan.transformer.TransformerImpl.executeChildTemplates(TransformerImpl.java:2411)
        at org.apache.xalan.templates.ElemChoose.execute(ElemChoose.java:139)
        at org.apache.xalan.transformer.TransformerImpl.executeChildTemplates(TransformerImpl.java:2411)
        at org.apache.xalan.templates.ElemChoose.execute(ElemChoose.java:139)
        at org.apache.xalan.transformer.TransformerImpl.executeChildTemplates(TransformerImpl.java:2411)
        at org.apache.xalan.templates.ElemChoose.execute(ElemChoose.java:139)
        at org.apache.xalan.templates.ElemApplyTemplates.transformSelectedNodes(ElemApplyTemplates.java:393)
        at org.apache.xalan.templates.ElemApplyTemplates.execute(ElemApplyTemplates.java:176)
        at org.apache.xalan.transformer.TransformerImpl.executeChildTemplates(TransformerImpl.java:2411)
        at org.apache.xalan.templates.ElemChoose.execute(ElemChoose.java:126)
        at org.apache.xalan.transformer.TransformerImpl.executeChildTemplates(TransformerImpl.java:2411)
        at org.apache.xalan.transformer.TransformerImpl.applyTemplateToNode(TransformerImpl.java:2281)
        at org.apache.xalan.transformer.TransformerImpl.transformNode(TransformerImpl.java:1367)
        at org.apache.xalan.transformer.TransformerImpl.transform(TransformerImpl.java:709)
        at org.apache.xalan.transformer.TransformerImpl.transform(TransformerImpl.java:1284)
        at org.apache.xalan.transformer.TransformerImpl.transform(TransformerImpl.java:1262)
        at org.apache.fop.cli.InputHandler.transformTo(InputHandler.java:165)
        at org.apache.fop.cli.InputHandler.renderTo(InputHandler.java:115)
        at org.apache.fop.cli.Main.startFOP(Main.java:166)
        at org.apache.fop.cli.Main.main(Main.java:197)
Caused by: java.lang.IllegalStateException: endElement() called for fo:root where there is no current element.
        at org.apache.fop.fo.FOTreeBuilder$MainFOHandler.endElement(FOTreeBuilder.java:367)
        at org.apache.fop.fo.FOTreeBuilder.endElement(FOTreeBuilder.java:194)
        at org.apache.xml.serializer.ToXMLSAXHandler.endElement(ToXMLSAXHandler.java:261)
        at org.apache.xalan.templates.ElemLiteralResult.execute(ElemLiteralResult.java:1399)
        at org.apache.xalan.templates.ElemApplyTemplates.transformSelectedNodes(ElemApplyTemplates.java:393)
        at org.apache.xalan.templates.ElemApplyTemplates.execute(ElemApplyTemplates.java:176)
        at org.apache.xalan.templates.ElemApplyTemplates.transformSelectedNodes(ElemApplyTemplates.java:393)
        at org.apache.xalan.templates.ElemApplyTemplates.execute(ElemApplyTemplates.java:176)
        at org.apache.xalan.transformer.TransformerImpl.executeChildTemplates(TransformerImpl.java:2411)
        ... 21 more
---------
java.lang.IllegalStateException: endElement() called for fo:root where there is no current element.
        at org.apache.fop.fo.FOTreeBuilder$MainFOHandler.endElement(FOTreeBuilder.java:367)
        at org.apache.fop.fo.FOTreeBuilder.endElement(FOTreeBuilder.java:194)
        at org.apache.xml.serializer.ToXMLSAXHandler.endElement(ToXMLSAXHandler.java:261)
        at org.apache.xalan.templates.ElemLiteralResult.execute(ElemLiteralResult.java:1399)
        at org.apache.xalan.templates.ElemApplyTemplates.transformSelectedNodes(ElemApplyTemplates.java:393)
        at org.apache.xalan.templates.ElemApplyTemplates.execute(ElemApplyTemplates.java:176)
        at org.apache.xalan.templates.ElemApplyTemplates.transformSelectedNodes(ElemApplyTemplates.java:393)
        at org.apache.xalan.templates.ElemApplyTemplates.execute(ElemApplyTemplates.java:176)
        at org.apache.xalan.transformer.TransformerImpl.executeChildTemplates(TransformerImpl.java:2411)
        at org.apache.xalan.templates.ElemIf.execute(ElemIf.java:160)
        at org.apache.xalan.transformer.TransformerImpl.executeChildTemplates(TransformerImpl.java:2411)
        at org.apache.xalan.templates.ElemChoose.execute(ElemChoose.java:139)
        at org.apache.xalan.transformer.TransformerImpl.executeChildTemplates(TransformerImpl.java:2411)
        at org.apache.xalan.templates.ElemChoose.execute(ElemChoose.java:139)
        at org.apache.xalan.transformer.TransformerImpl.executeChildTemplates(TransformerImpl.java:2411)
        at org.apache.xalan.templates.ElemChoose.execute(ElemChoose.java:139)
        at org.apache.xalan.templates.ElemApplyTemplates.transformSelectedNodes(ElemApplyTemplates.java:393)
        at org.apache.xalan.templates.ElemApplyTemplates.execute(ElemApplyTemplates.java:176)
        at org.apache.xalan.transformer.TransformerImpl.executeChildTemplates(TransformerImpl.java:2411)
        at org.apache.xalan.templates.ElemChoose.execute(ElemChoose.java:126)
        at org.apache.xalan.transformer.TransformerImpl.executeChildTemplates(TransformerImpl.java:2411)
        at org.apache.xalan.transformer.TransformerImpl.applyTemplateToNode(TransformerImpl.java:2281)
        at org.apache.xalan.transformer.TransformerImpl.transformNode(TransformerImpl.java:1367)
        at org.apache.xalan.transformer.TransformerImpl.transform(TransformerImpl.java:709)
        at org.apache.xalan.transformer.TransformerImpl.transform(TransformerImpl.java:1284)
        at org.apache.xalan.transformer.TransformerImpl.transform(TransformerImpl.java:1262)
        at org.apache.fop.cli.InputHandler.transformTo(InputHandler.java:165)
        at org.apache.fop.cli.InputHandler.renderTo(InputHandler.java:115)
        at org.apache.fop.cli.Main.startFOP(Main.java:166)
        at org.apache.fop.cli.Main.main(Main.java:197)

D:\wrk\BookTest>