Problem transforming self generated events...

[Ji...@mortgage.wellsFargo.COM]

I am having a problem doing a transformation on a set of 
SAX events that I am generating myself. If I send the output
directly to an xml serializer, the output looks just as I expect:
 
My Events => Serializer => output looks fine
 
 
However, when I attempt to put my events through a transform,
I get the following stack trace:
 
java.lang.RuntimeException: java.lang.NullPointerException
            at
org.apache.xalan.transformer.TransformerImpl.run(TransformerImpl.java:3392)
            at
org.apache.xalan.transformer.TransformerHandlerImpl.endDocument(TransformerH
andlerImpl.java:433)
            at
com.wellsfargo.mortgage.struts.xsl.XSLServlet$XMLInputEventStream.toSAX(XSLS
ervlet.java:157)
            at
com.wellsfargo.mortgage.struts.xsl.XSLServlet.processMapping(XSLServlet.java
:129)
            ...
 
So, I end the document and the transformation tries to begin, but it fails:
 
My Events => Transformation (fails here) => Serializer
 
 
If I run the transformation from an xml file on disk using an XMLReader,
things work fine:
 
Disk file => XMLReader => Transformation => Serializer => output looks fine
 
 
I've looked at the TransformerImpl.java code. Unfortunately, the line in
question hides the original exception
so I don't know where the real problem begins :( 
 
I would appreciate any ideas on what might be happening or what I can do to
further debug the problem.
I can provide some code fragments if it helps.
 
Cheers,
Jim.
 
James J. Majure
Systems Architect
Wells Fargo Services Company
515.213.4870