question about XSLTC

I'm new to xalan, when I tried this command for samples

C:\xalan\samples\SimpleTransform>java org.apache.xalan.xsltc.cmdline.Transform b
irds.xsl birds

I got the following error messages:

Exception in thread "main" java.lang.IllegalAccessError: class org.apache.xml.dt
m.ref.sax2dtm.SAX2DTM2$AncestorIterator cannot access its superclass org.apache.
xml.dtm.ref.DTMDefaultBaseIterators$InternalAxisIteratorBase
        at java.lang.ClassLoader.defineClass0(Native Method)
        at java.lang.ClassLoader.defineClass(Unknown Source)
        at java.security.SecureClassLoader.defineClass(Unknown Source)
        at java.net.URLClassLoader.defineClass(Unknown Source)
        at java.net.URLClassLoader.access$100(Unknown Source)
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClassInternal(Unknown Source)
        at org.apache.xalan.xsltc.dom.XSLTCDTMManager.getDTM(XSLTCDTMManager.jav
a:351)
        at org.apache.xalan.xsltc.dom.XSLTCDTMManager.getDTM(XSLTCDTMManager.jav
a:159)
        at org.apache.xalan.xsltc.cmdline.Transform.doTransform(Transform.java:1
26)
        at org.apache.xalan.xsltc.cmdline.Transform.main(Transform.java:297)


Can anyone tell me what is wrong here? 

Thank you,


Jun