ми аз не виждам проблем ....

ceco@c92-100:~/tmp$ cat test_call_func.php
<?
class eho {
function beho($param) {
echo "eho - beho - $param\n";
}
}

call_user_func_array(array('eho', 'beho'), array('Вълчо'));
?>
ceco@c92-100:~/tmp$ php test_call_func.php
eho - beho - Вълчо

пробвах го с
PHP 4.3.10-15 (cli) (built: May 9 2005 08:54:56)
Copyright (c) 1997-2004 The PHP Group
Zend Engine v1.3.0, Copyright (c) 1998-2004 Zend Technologies

също и с
PHP 5.1.0-dev (cli) (built: Jul 28 2005 12:37:11)
Copyright (c) 1997-2005 The PHP Group
Zend Engine v2.1.0-dev, Copyright (c) 1998-2004 Zend Technologies