Delegation Assersion - Message was signed, but signature could not be verified.

[Eddie Harari]

Hello ,

   When trying to present the assertion with the "back service" SP I
am getting the following  error from the SP :

 Message was signed, but signature could not be verified.

  The metadata is configured with the correct IDP certificate, and
this message only comes when i am using delegation , when i use the
"simple" redirect profile , the SP understands the IDP signature.

 any idea of what can be wrong here ?

thanks ,

 Eddie.