Using proxy in Soap Adapter

Hi,

I have a orchestation with a send port connected with a SOAP adapter consuming a web service. I have configured a proxy assembly in send port to consume the web service but  when I run the orchestation I received the error:

Event Log

Failed to serialize the message part “OrdersIn” into the type “OrdersIn” using namespace “http://tenaris.com/Sales/SaleOrdersSAP”. Please ensure that the message part stream is created properly. 

I’m using BizTalk 2006 R2 and Soap Adapter.

Thanks in advace.