WS-AT Issue between WPS 6.2 and WAS 7.0

Question

Hi, I have a BPEL running on WPS 6.2 trying to call a web service on developed on RAD 7.5, deployed on RAD test environment. I have setup WS Transaction policy on both client and server. I get an error on WAS 7.0 saying

Must Understand check failed for headers: {http:// schemas.xmlsoap.org/ws/2004/10/wscoor}CoordinationContext

I tried to generate the same webservice on ibm wid 6.2 and deployed on EAR on WAS 7, it works perfect.

Any thoughts ? Is there a SOAP runtime mismatch ?

Help appreciated .

-AK