We use the following gateway to handle the amf requests:

<?php
ini_set("display_errors", 1);
$dir = dirname(__FILE__);
$webroot = $_SERVER['DOCUMENT_ROOT'];
$configfile = "$dir/amf_config.ini";

//default zend install directory
$zenddir = $webroot. '/ZendFramework/library';

//Load ini file and locate zend directory
if(file_exists($configfile)) {
    $arr=parse_ini_file($configfile,true);
    if(isset($arr['zend']['zend_path'])){
        $zenddir = $arr['zend']['zend_path'];
    }
}


// Setup include path
    //add zend directory to include path
set_include_path(get_include_path().PATH_SEPARATOR.$zenddir);
// Initialize Zend Framework loader
require_once 'Zend/Loader/Autoloader.php';
Zend_Loader_Autoloader::getInstance();
// Load configuration
$default_config = new Zend_Config(array("production" => false), true);
$default_config->merge(new Zend_Config_Ini($configfile, 'zendamf'));
$default_config->setReadOnly();
$amf = $default_config->amf;

// Store configuration in the registry
Zend_Registry::set("amf-config", $amf);
// Initialize AMF Server
$server = new Zend_Amf_Server();
$server->setProduction($amf->production);
if(isset($amf->directories)) {
    $dirs = $amf->directories->toArray();
    foreach($dirs as $dir) {
        $server->addDirectory($dir);
    }
}

// Initialize introspector for non-production
if(!$amf->production) {
    $server->setClass('Zend_Amf_Adobe_Introspector', '', array("config" => $default_config, "server" => $server));
    $server->setClass('Zend_Amf_Adobe_DbInspector', '', array("config" => $default_config, "server" => $server));
}
// Handle request
echo $server->handle();

With Zend framework 1.8.3 this works fine, but with Zend Framework 1.8.4, we receive the following error:

Server error Class "EmployeeService" does not exist 
#0 C:\wamp\www\ZendFramework\library\Zend\Amf\Server.php(540): Zend_Amf_Server->_dispatch('count', Array, 'EmployeeService') 
#1 C:\wamp\www\ZendFramework\library\Zend\Amf\Server.php(616): Zend_Amf_Server->_handle(Object(Zend_Amf_Request_Http)) 
#2 C:\wamp\www\TestZend184-debug\gateway.php(49): Zend_Amf_Server->handle() 
#3 {main}