Siebel Sample is not working when Enable DeDuplication is enabled in System Preference.

I am using the SOAP message for the UCM Process with System Preference "Enable Deduplicaiton" set "TRUE". Which is leading to an HTTP error.  (in SoapUI). Problem exists due to searching the third party Matching set-up (Which I am not using)

Soap Message:

<swip:ListOfSwiPersonIO ExternalSystemId="1001">

     <swip:Contact  operation="Upsert">

               <swip:Id>67788</swip:Id>

               <swip:EmailAddress></swip:EmailAddress>

               <swip:FirstName>Mary</swip:FirstName>

               <swip:LastName>Borg</swip:LastName>

</swip:Contact>

         </swip:ListOfSwiPersonIO>

This will work fine, if Deduplication is set to false.

On Environment, i am trying to leverage the Sample Database and SSA  capability which is OOTB with UCM.