Secure Join Windows 8 presaged machine

Hi,

I'm trying to Secuire Join  a PC to the domain but it those not join it, I can join the pc with the same credentials after install

<?xml version="1.0" encoding="utf-8"?>

<unattend xmlns="urn:schemas-microsoft-com:unattend">
    <settings pass="specialize">
        <component name="Microsoft-Windows-Shell-Setup" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="nonSxS" xmlns:wcm="http://schemas.microsoft.com/WMIConfig/2002/State" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
            <ComputerName>%MACHINENAME%</ComputerName>
            <ProductKey>serial</ProductKey>
        </component>
        <component name="Microsoft-Windows-UnattendedJoin" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="nonSxS" xmlns:wcm="http://schemas.microsoft.com/WMIConfig/2002/State" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
            <Identification>
                <UnsecureJoin>false</UnsecureJoin>
<Credentials>
                    <Domain>domain</Domain>
                    <Password>pass</Password>
                    <Username>user</Username>
                </Credentials>
            </Identification>
        </component>
    </settings>
    <cpi:offlineImage cpi:source="wim:c:/distribution%20share/win%208.wim#Windows 8 Pro" xmlns:cpi="urn:schemas-microsoft-com:cpi" />
</unattend>

http://technet.microsoft.com/en-us/library/cc732280(v=ws.10).aspx#Image2