Forbidden Error while using SOAP web service For Message Center

Hi

I am fairly new to campaing and was wonder if anyone can help me solve this issue.

We have MC setup .  I am able to get the login session token via SOAP service  for a user . I use the Session token to make a call to MC and it fails with following error

I have made sure that

1.      User has read/write rights over the message Schema that was created for MC
2.      User has been given administrator access on adobe campaing
3.      The   allowUserPassword="true"  sessionTokenOnly="true" for the there securtyZone viz  Lan, VPN and Public
4.     The user is assigned Message Center Named right  ( see figure below )

<SOAP-ENV:Envelope xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/">

   <SOAP-ENV:Body>

      <SOAP-ENV:Fault>

         <faultcode>SOAP-ENV:Server</faultcode>

         <faultstring xsi:type="xsd:string">SOP-330011 Error while executing the method 'postMessage' of service 'agsc:mc_messagesInformation'.</faultstring>

         <detail xsi:type="xsd:string">INT-150012 The HTTP query returned a 'Forbidden' type error (403)

(1:1) : Invalid document structure

XML-110018 Error while parsing XML string 'XSV-350115 The user/password authentication is not authorized for 'mc' login via the '0:0:0:0:0:0:0:1' address.                                                                                                                                  '</detail>

      </SOAP-ENV:Fault>

   </SOAP-ENV:Body>

</SOAP-ENV:Envelope>