eclipse launch xsl transformation with extension functions

Hi all,

I am trying to test an XSL extension function by launching the XSL from 
Eclipse -- so far, with no success :(

The configuration is as follows:
1. Eclipse Galileo with the XSL feature
2. Defined an XSL run configuration with the Xalan 2.7.1 processor

I am able to launch the XSL transformation, however the reference to my 
custom Java extension class is ignored.

This is my XSL header:

<xsl:stylesheet version="1.0"
   xmlns:xsl="http://www.w3.org/1999/XSL/Transform" 
xmlns:tl="http://foo.com//lang/1.0"
   xmlns:tc="http://qcore.com/pump/testing/commands/1.0" 
xmlns:xalan="http://xml.apache.org/xalan"
   xmlns:utils="com.foo@%#$%@#^#%#$"
   extension-element-prefixes="utils">


I discovered that no matter what the contents of xmlns:util are, the XSL 
process treats them as "java.lang"; that is, all java.lang classes are 
available and called successfully!

Any suggestion(s)?
What should I check further?

Thanks in advance,
Adrian.