[xml] DOMXML interdependancies

["Peter Bayley" <peterb homer com au>]

I have successfully compiled PHP4.2.0 with the --with-dom= syntax etx and
installed it as an apache module.
phpinfo() gives me:

DOM/XML              enabled
libxml Version           2.4.19
HTML Support         enabled
XPath Support          enabled
XPointer Support      enabled
DOM/XSLT             enabled
libxslt Version            enabled

but
<?php
$prt=domxml_file_open('ilsPrinters.xml');
?>

gives me:

Fatal error: Call to undefined function: domxml_file_open()

Could it be some interdependencies?  There are no errors but teh calls are
not visible PHP?

Thanks in advance

Peter