IncompatibleClassChangeError due to throws clauses not matching between JaxenHandler and XPathHandler

Following exception occurs intermittently:

Uncaught exception
java.lang.IncompatibleClassChangeError: Class org.jaxen.JaxenHandler does not
implement the requested interface org.jaxen.saxpath.XPathHandler
at org.jaxen.saxpath.base.XPathReader.parse(XPathReader.java:98)

The line is:

getXPathHandler().startXPath();
in XPathReader.parse.

We have debugged a similar error in other code previously. The error is caused by the throws clauses not matching between the implementation and the interface (JaxenHandler implementing XPathHandler). In the particular call the startXPath method is defined by the interface to throw a SAXPathException and the implementation throws no exception. It appears all of the methods in JaxenHandler are inconsistent either throwing nothing or throwing a JaxenException.
Even though this is an intermittant issue it should be corrected. Once it appears there seems to be a tendency for the user to see it many times over. The user has to restart their application before they can resume what they are working on.