Cannot update Lenya Website: Exception while trying to "Update Code Changes"

I'm unable to update the changes in the lenya website authoring area to the SVN; 
this throws an exception:

Caused by: java.lang.RuntimeException: org.tmatesoft.svn.core.SVNException: svn: Parser configuration problem: namespace reporting is not enabled
 	at org.apache.lenya.modules.forrest.UpdateChanges$LogEntryHandler.handleLogEntry(UpdateChanges.java:199)

  ...

Caused by: org.tmatesoft.svn.core.SVNException: svn: Parser configuration problem: namespace reporting is not enabled
 	at org.tmatesoft.svn.core.internal.wc.SVNErrorManager.error(SVNErrorManager.java:82)
 	at org.tmatesoft.svn.core.internal.wc.SVNErrorManager.error(SVNErrorManager.java:69)
 	at org.tmatesoft.svn.core.wc.xml.SVNXMLLogHandler.handleLogEntry(SVNXMLLogHandler.java:138)
 	at org.apache.lenya.modules.forrest.UpdateChanges$LogEntryHandler$Month.handleLogEntry(UpdateChanges.java:167)
 	at org.apache.lenya.modules.forrest.UpdateChanges$LogEntryHandler.handleLogEntry(UpdateChanges.java:197)
 	... 108 more
Caused by: org.xml.sax.SAXException: Parser configuration problem: namespace reporting is not enabled
 	at net.sf.saxon.event.ReceivingContentHandler.getNameCode(ReceivingContentHandler.java:401)
 	at net.sf.saxon.event.ReceivingContentHandler.startElement(ReceivingContentHandler.java:278)
 	at org.apache.cocoon.xml.AbstractXMLPipe.startElement(AbstractXMLPipe.java:95)
 	at org.tmatesoft.svn.core.wc.xml.AbstractXMLHandler.openTag(AbstractXMLHandler.java:81)
 	at org.tmatesoft.svn.core.wc.xml.SVNXMLLogHandler.sendToHandler(SVNXMLLogHandler.java:157)
 	at org.tmatesoft.svn.core.wc.xml.SVNXMLLogHandler.handleLogEntry(SVNXMLLogHandler.java:135)


To me it looks like an incompatibility with the saxon parser: though the second 
parameter of org.apache.cocoon.xml.AbstractXMLPipe.startElement is explicitly 
allowed to be the empty string if Namespace processing is not being performed, 
the saxon parser always performs namespace handling and throws this exception.

See: http://markmail.org/message/ag3t7xzyf6nyrsts

HELP?

    Rainer