Enterprise Manager

I have this setup where dbs are being copied across different environments production, test and user testing. The project is not in production yet and the method used to refresh other environments from "production" has been to stop the dbs, copy the datafiles over to the other environments and restart the dbs. In so doing, the database name, instance name and this interesting parameter DB_UNIQUE_NAME are all the same.
It looks to me that Grid Control can not deal with this? In any case, i can have the target name as a different name and it looks like it works. But i was also setting up dataguard and i started getting errors like DB_UNIQUE_NAME has to be unique in the enterprise in Grid Control.

So, my question is do you all have a different DB_UNIQUE_NAME in Grid Control?
Environment is Grid Control 10g R3 on windows, target dbs are on solaris 10 and they are at 10.2.0.3.
Thanks.