A good think would be to provide an Ant buildfile, as well as a Java class, that show the XRN runtime dependencies.
This buildfile would be a good starting point in order to fully undertstand the classpath to be used in order to use the Ant task.
It would also be the opportunity to test it against various (JRE, Ant, Xalan, Saxon) configurations...
For info the run time dependancies are :
With ant you need to define thge ANT_OPT :