Xalan also works. I posted an example of a bug in xalan at: http://www.vhikida.com/docbook/docbook.html
You should use the chunk.xsl that comes with docbook-xsl 1.51.1. The bug posted was created with 1.50.0. Also posted is an example of ant build file using xalan rather than running from the command line. Be sure to use an XSLT processor that supports chunking (e.g. Saxon or XSLTProc).
