RRDI throws "Unknow Server" error whlie collaborating with JTS Server

I am configuring RRDI for a customer who has RTC 3.0.1.1 with RRDI 1.0.2.1. While logging to RRDI Server I get  " Will you allow server "<Unknown Server>" to collaborate with Server https://<hostname>:port/jts using user ID < Showing user Id just entered for login >.

I have checked that RRDI Installation is perfect as in the same Host another RTC Instance is Running on different TOMCAT port and RRDI is perfectly working AND I can bring out Reports from RRDI

RRDI database ( RICM & RIDW ) are in DB2 .
The etl log shows that RIDW is populated without authentication error after running the dataware house jobs
If I go to the tables of RIDW , I see the data in Tables ( e,g D_PROJECT etc )
BUT from RRDI I can't run any report as it gives " Unknown Server " .
Sometimes it goes directly to RRDI , then from the ODS tables if I run any query it says "No Data Available"


I strongly feel that there is problem in the other RTC instance -- NOT able to find out where is the problem .
It will great if someone helps me

Thanks

PKC