WSDL :

<complexType name="A">
    <sequence>
      <element name="a" type="xsd:int"/>
    </sequence>
</complexType>

<complexType name="B">
  <complexContent>
     <extension base="impl:A">
	<sequence>
          <element name="b" type="xsd:int"/>
        </sequence>
     </extension>
  </complexContent>
</complexType>

I just committed test file ext/soap/tests/schema/schema085.phpt, that demonstrates proper element ordering. In your example you probably do somthing wrong. I cannot say that exactly is wrong as you didn't provide full reproduce case, probably you object isn't encoded using WSDL.
In case if you like me to look into problem please provide full example (without ...) including full WSDL file.

No feedback was provided for this bug for over a week, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".

Hello Dmitry,

Our situation is a bit different than what you have tested.
Here is the link to the WSDL :

http://213.41.94.84/wsPricing/services/PricingSNC?wsdl

Look at the complexType named "WSParameters".
It contains an element "loan" which type is "WSLoan".
But two types extend WSLoan : "WSLoanClassic" and "WSLoanPerso".

The Web Service expects us to send either of the inherited type.
WSLoan is an abstract type.

So in our case the correct type is not directly defined like in your
test case.

We are using SoapVar to specify the correct type of our object.
Then the generated SOAP request references the correct type.
But the fields are in the wrong order.

As you can see the WSDL file is generated by Apache Axis.

Not reprodusable.

Reproduce code:
---------------
<?php
class Loan {
	public $startingDate = "01-Jan-2007";
	public $amount;
	public $duration;
}
class LoanPersoItem {
	public $year;
	public $amount;
}
class LoanPerso extends Loan {
	public $loans;
}

$client = new SoapClient("http://213.41.94.84/wsPricing/services/PricingSNC?wsdl",
	array(
		"location" => "test://",
		"trace" => 1,
		"exceptions" => 0,
	)
) ;

$v = new LoanPerso();
$v->loans = new LoanPersoItem();
$var = new SoapVar($v , SOAP_ENC_OBJECT, 'WSLoanPerso', 'http://pricing.aigvienet/gb/snc/' ) ;

$client->processPricingSNC(
	array(
		"insured" => array(
			"name" => "Aaa",
			"firstname" => "Bbb",
			"birthdate" => "01-Jan-2006"
		),
		"premiumMode" => 0,
		"loan" => $var,
		"option" => array(),
		"productCode" => "XXX"
	)
) ;
echo $client->__getLastRequest();
?>

Output:
-------
<?xml version="1.0" encoding="UTF-8"?>
<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ns1="http://pricing.aigvienet/gb/snc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><SOAP-ENV:Body><ns1:processPricingSNC><parametres><ns1:insured><ns1:name>Aaa</ns1:name><ns1:firstname>Bbb</ns1:firstname><ns1:birthdate>01-Jan-2006</ns1:birthdate><ns1:profession xsi:nil="true"/></ns1:insured><ns1:premiumMode>0</ns1:premiumMode><ns1:loan xsi:type="ns1:WSLoanPerso"><ns1:startingDate>01-Jan-2007</ns1:startingDate><ns1:amount xsi:nil="true"/><ns1:duration xsi:nil="true"/><ns1:loans><ns1:year xsi:nil="true"/><ns1:amount xsi:nil="true"/></ns1:loans></ns1:loan><ns1:option/><ns1:promotional xsi:nil="true"/><ns1:quotity xsi:nil="true"/><ns1:couple xsi:nil="true"/><ns1:smoker xsi:nil="true"/><ns1:ds xsi:nil="true"/><ns1:productCode>XXX</ns1:productCode></parametres></ns1:processPricingSNC></SOAP-ENV:Body></SOAP-ENV:Envelope>

Hi !

Thanks for your help.
We found the problem, the service provider had changed 
the namespace URI without notifying us.
it is working with the correct URI.