I searched the bug database for "is_a" but found no entries, so I thought I should post this here...

The code below always prints "failed!!!":

<?php
$dom = domxml_new_doc("<?xml version=\"1.0\"?" . "><me><name>Joe Cool</name><age>24</age><gender>male</gender></me>");
$elem = $dom->create_element("aaa");
// any of the if's below fails
if ( is_a( $elem, "DomElement" ) )
// if ( is_a( $elem, get_class( $elem ) ) )
{
   echo "OK\n";
}
else
{
   echo "failed!!!\n";
}
?>

My config line was:

./configure '--prefix=/usr' '--exec-prefix=/usr' '--bindir=/usr/bin' \
'--sbindir=/usr/sbin' '--sysconfdir=/etc' '--datadir=/usr/share' \
'--includedir=/usr/include' '--libdir=/usr/lib' \
'--libexecdir=/usr/libexec' '--localstatedir=/var' \
'--sharedstatedir=/usr/com' '--mandir=/usr/share/man' \
'--infodir=/usr/share/info' '--prefix=/usr' \
'--with-config-file-path=/etc'  '--enable-force-cgi-redirect' \
'--disable-debug' '--enable-pic' '--disable-rpath' \
'--enable-inline-optimization' '--with-bz2' '--with-db3' \
'--with-exec-dir=/usr/bin' '--with-gd' '--with-gdbm=/usr' \
'--with-gettext' '--with-gmp' '--with-jpeg-dir=/usr' '--with-mm' \
'--with-openssl' '--with-png' '--with-pspell' '--with-regex=system' \
'--with-xml' '--with-dom=/usr' '--with-expat-dir=/usr' '--with-zlib' \
'--with-layout=GNU' '--enable-bcmath' '--enable-debugger' '--enable-ftp' \
'--enable-magic-quotes' '--enable-safe-mode' '--enable-sockets' \
'--enable-sysvsem' '--enable-sysvshm' '--enable-track-vars' \
'--enable-trans-sid' '--enable-yp' '--enable-wddx' '--without-oci8' \
'--with-kerberos=/usr/kerberos' '--with-sybase=/usr/local/freetds' \
'--with-apxs=/usr/sbin/apxs' '--enable-cli'

The output of 'php -m' is:

costa:~/public_html php -m
Running PHP 4.2.1
Zend Engine v1.2.0, Copyright (c) 1998-2002 Zend Technologies

[PHP Modules]
yp
xml
wddx
sysvshm
sysvsem
sybase
standard
sockets
session
pspell
posix
pcre
openssl
mysql
gmp
gettext
gd
ftp
domxml
dba
ctype
bz2
bcmath
zlib
session mm

[Zend Modules]

-----
on the above example, replacing the test for

if ( get_class( $elem ) == "DomElement" )

works.

Let me know if you need more info.

Best,

Andre