Web Service security header validation on WebLogic - web-services

Question

I have a web service deployed on WebLogic that has a usernameToken security policy. I implemented my own Java password validator (that extends com.sun.xml.wss.impl.callback.PasswordValidationCallback.WsitDigestPasswordValidator).
<wsp:Policy wsu:Id="DoubleItBindingPolicy">
<wsp:ExactlyOne>
<wsp:All>
<wsam:Addressing wsp:Optional="false"/>
<sp:TransportBinding>
<wsp:Policy>
<sp:TransportToken>
<wsp:Policy>
<sp:HttpsToken RequireClientCertificate="false"/>
</wsp:Policy>
</sp:TransportToken>
<sp:Layout>
<wsp:Policy>
<sp:Lax/>
</wsp:Policy>
</sp:Layout>
<sp:IncludeTimestamp/>
<sp:AlgorithmSuite>
<wsp:Policy>
<sp:Basic128/>
</wsp:Policy>
</sp:AlgorithmSuite>
</wsp:Policy>
</sp:TransportBinding>
<sp:SignedEncryptedSupportingTokens>
<wsp:Policy>
<sp:UsernameToken sp:IncludeToken="http://docs.oasis-open.org/ws-sx/ws-securitypolicy/200702/IncludeToken/AlwaysToRecipient">
<wsp:Policy>
<sp:WssUsernameToken10/>
</wsp:Policy>
</sp:UsernameToken>
</wsp:Policy>
</sp:SignedEncryptedSupportingTokens>
<sc:ValidatorConfiguration wspp:visibility="private">
<sc:Validator name="usernameValidator" classname="service.PasswordValidator"/>
</sc:ValidatorConfiguration>
<sp:Wss11/>
</wsp:All>
</wsp:ExactlyOne>
</wsp:Policy>
My problem is that when i try to invoke my web service using a SOAP message containing the security header, the header is completely ignored, as if the web service has no security attached.
I have tried creating in the WebLogic console a new Web Service Security configuration and reference it in my service's class using the annotation WssConfiguration, but the result is the same.
I have also tried adding a WS-Policy to my WebService ( policy:Wssp1.2-2007-Wss1.1-UsernameToken-Digest-DK.xml), and still the same.
Could you please tell how to activate the validation of my SOAP message security header in WebLogic?