SOAP Webservice call with attributes from within Orchestrator

I'm attempting to call a SOAP 1.2 Webservice from a System Center Orchestrator 2012. I've first tested my call through both Powershell and SOAPUI which give no errors. However when I try to do send the same SOAP Request using the builtin 'Invoke Web Services' utility from SCORCH it appears like my attributes are being ignored. (cause the request to fail).

The definition of the Webservice is as followed:

<?xml version="1.0" encoding="utf-8"?>
<soap12:Envelope xmlns:xsi="http://ift.tt/ra1lAU"          xmlns:xsd="http://ift.tt/tphNwY" xmlns:soap12="http://ift.tt/18hkEkn">
      <soap12:Body>
        <AddObject xmlns="http://ift.tt/1uiIl3J">
          <Object folderPath="string" fieldMapping="string" saveExFlags="int" username="string" password="string" />
        </AddObject>
      </soap12:Body>
    </soap12:Envelope>

My SCORCH activity is defined as

Activiy Details

For some reason, SCORCH seems to ignore any attributes inside of an element. This causes the XML to not have the correct formatting/insufficient data and my call fails.

Does anybody have any experience using a (complextype) SOAP Webservice from within Orchestrator with success? The same call works fine from Powershell so I'm positive my Webservice itself is fine.

Any help in the right direction would be appreciated.