DOCBOOK-APPS: xsl stylesheets 1.49 chunker error

[Gary Lawrence Murphy <garym@canada.com>]

If I had more information, I'd include a sample, but as it is, I'm
mystified: I have a DocBook/XML 1.4.2 document which can be transformed
without incident using the html/docbook.xsl or the fo/docbook.xsl but
when run through xalan-2.2.0-dev and xerces-1.4.4 using html/chunk.xsl
it aborts with the very uninformative error:

(Location of error unknown)XSLT Error
(javax.xml.transform.TransformerConfigurationException): 500

1) is there any way to narrow down this error more precisely short of
   a newtonian bi-section search progressively deleting half the doc?

2) is there a reference anywhere for the Transformer error codes?

-- 
Gary Lawrence Murphy <garym@teledyn.com> TeleDynamics Communications Inc
Business Innovations Through Open Source Systems: http://www.teledyn.com
"Computers are useless.  They can only give you answers."(Pablo Picasso)