PDF export exception - 'The processing instruction target matching "[xX][mM][lL]" is not allowed'

Hi all, Using XWiki 0.9.840 I get systematically the error below when trying to export any document to PDF. Do you have any idea about it? I tried both UTF-8 and ISO-8859-1 encodings and I got the same result. The XML conversion works fine. Stéphane ================================ com.xpn.xwiki.XWikiException: Error number 12003 in 12: XSL Transformation Failed Wrapped Exception: The processing instruction target matching "[xX][mM][lL]" is not allowed. at com.xpn.xwiki.pdf.impl.PdfExportImpl.applyXsl(PdfExportImpl.java:176) at com.xpn.xwiki.pdf.impl.PdfExportImpl.convertXHtmlToXMLFO(PdfExportImpl.java:154) at com.xpn.xwiki.pdf.impl.PdfExportImpl.exportXHtml(PdfExportImpl.java:86) at com.xpn.xwiki.pdf.impl.PdfExportImpl.exportHtml(PdfExportImpl.java:115) at com.xpn.xwiki.pdf.impl.PdfExportImpl.export(PdfExportImpl.java:129) at com.xpn.xwiki.pdf.impl.PdfExportImpl.exportToPDF(PdfExportImpl.java:119) at com.xpn.xwiki.XWikiService.renderPDF(XWikiService.java:969) ================================ -- Stéphane Laurière slauriere(a)mandriva.com