jaxp 1.4 on jre 1.4.2

Dear all,

I am trying to use the jaxp 1.4 standalone download from java.net with
Sun JRE 1.4.2. Here is a minimal test class:

import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathFactory;

import org.w3c.dom.Document;

public class TestJaxp {
    public static void main(String[] args) throws Exception {
        Document doc = DocumentBuilderFactory.newInstance()
                .newDocumentBuilder().newDocument();
        XPath xpath = XPathFactory.newInstance().newXPath();
        xpath.evaluate("/", doc);
    }
}

It fails with:

java.lang.NoClassDefFoundError: com/sun/org/apache/xalan/internal/
extensions/ExpressionContext
    at
com.sun.org.apache.xpath.internal.jaxp.XPathImpl.eval(XPathImpl.java:
201)
    at
com.sun.org.apache.xpath.internal.jaxp.XPathImpl.evaluate(XPathImpl.java:
275)
    at
com.sun.org.apache.xpath.internal.jaxp.XPathImpl.evaluate(XPathImpl.java:
365)
    at TestJaxp.main(TestJaxp.java:13)
Exception in thread "main"

My classpath consists of this class followed by jaxp-api.jar then jaxp-
ri.jar.

What am I doing wrong?

Thanks,

Matt