XML signature

I am trying to create a request with XML signature with soapUI. The created message looks like this:


 

1xeWb10a3EIXvGOSPh/82tjxul4=



Bv20lY0H4QM6JCOan......xtPm6N7kEiGnfwVFeSMSfXqyQ==


MIIEDj.....Ap+oBbPcw==


      urn:carelink:bif:authz:0.1:EvaluateXACML30Request
 

 
      anyType
 


The problem I have is that the server reject my message:
"Verification of Signature with ID  Signature-10748469 failed, possible cause : proper canonicalizedsignedinfo was not produced."

It looks likte it is impossible to calculate the value for the server. What I am missing in the request is a  prefix list. Example:
     
       
         
==>           
         
         
         
           
             
==>           
             
           
                        RSYxyDk+tlgcNt/C+SUq6rU7tJQ=
         
       

So, my question is if you use prefix in your calculation but the prefix list is not added in the request?