Hi rmg,
Thanks for the reply.
I set the membership as XML in prod too but it failed again.
The issue is that we are not getting transfer report from partner on secure HTTPS URL so Issue seems to be SSL related.we are successfully getting report on HTTP URL
What we did - we placed partner root and public certificate in trusted dir of IS and mapped it from admin console to user name.Also user name is associated with Everybody and TNPartners ACL.
Service invoked by partner is having access control as Default
List ACL (inherited)
Read ACL (inherited)
Write ACL (inherited)
Execute ACL TNPartners
Enforce ACL on Internal Invokes Off
Our set up is that we have 2 RI server and 2 IS 6.5 in cluster.
So whether there is any issue with ACL or certificate(which are valid) but their placement in RI or IS or any configuration in TN.
Please help me out on this , I have tried all things and its going out of control 
Thanks
-Hemendra
#B2B-Integration#Integration-Server-and-ESB#webMethods