DOCBOOK-APPS: is not being recognized as an element

[Robert P. J. Day]

  i'm writing some fairly simple docbook in red hat 8.0, which
has the docbook 4.2 dtd, which allegedly supports the <errortext>
element.

  i've verified that that DTD directory is there under
/usr/share/sgml/docbook, that "xmlcatalog" properly resolves
the public identifier to that location, i've tried explicitly
setting XML_CATALOG_FILES=/etc/xml/catalog just to play it safe,
but nothing i do seems to be able to recognize <errortext>.

  hints?

rday