Description:
------------
PHP SoapClient seems to have trouble making calls when the WSDL has two or more port bindings present that share function names

Reproduce code:
---------------
<?php
class mySoapClient extends SoapClient {

	public function __doRequest( $request, $location, $action, $version, $one_way ){
		print_r( 'SOAPAction: "' . $action . '"<br>' );
		return '';		// Response is not important here 
	}
	
}

$wsdl = 'http://www.vicomstudio.com/alejandro/WSDL2.wsdl';
$ws = new mySoapClient( $wsdl, array( 'trace' => true ) );

// Create an example request
$response = $ws->listOffers( array(
		'keywords' => 'dvd',
		'itemPage' => 1,
		'merchantID' => array( 'value' => 'Amazon' ),
		'category' => array( 'name' => 'Automotive', 'value' => 'Automotive' )
	)
);

?>

Expected result:
----------------
SOAPAction: "listOffers"

Actual result:
--------------
SOAPAction: ""