cannot have child contents to be deserialized as an object

I've found a way to make the XML work in soapUI.
Hopefully this will be helpful if anyone else runs into the same problem.
I was able to capture the XML being sent by my Visual Studio application to the Web Service.
(I used a handy, free tool called Fiddler: http://www.fiddler2.com/fiddler2/ ).

<soap:Envelope xmlns:soap="http://www.w3.org/2003/05/soap-envelope" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
 <soap:Body>
  <startProcess xmlns="http://tempuri.org/">
   <requestDetails>
      <loginRequest xmlns="http://schemas.datacontract.org/2004/07/XXX.SystemLib.Interfaces" >
     <LoginID xmlns="http://schemas.datacontract.org/2004/07/XXX.SystemLib.Interfaces">manager</LoginID>
     <Password xmlns="http://schemas.datacontract.org/2004/07/XXX.SystemLib.Interfaces">pretendPwd</Password>
      </loginRequest>
      <Command xmlns="http://schemas.datacontract.org/2004/07/XXX.SystemLib.Interfaces">create</Command>
      <EntityName xmlns="http://schemas.datacontract.org/2004/07/XXX.SystemLib.Interfaces">customer</EntityName>
   </requestDetails>
   <processParameters>
      <Parameters xmlns="http://schemas.datacontract.org/2004/07/XXX.SystemLib.Interfaces">
     <Key>cust_id</Key>
     <Value xsi:type="xsd:string">WLMT</Value>
      </Parameters>
      <Parameters xmlns="http://schemas.datacontract.org/2004/07/XXX.SystemLib.Interfaces">
     <Key>descr</Key>
     <Value xsi:type="xsd:string">Walmart</Value>
      </Parameters>
   </processParameters>
  </startProcess>
 </soap:Body>
</soap:Envelope>

SIDE NOTE: One thing I especially noticed was xsi:type="xsd:string" in the <Value> tags.