can't backup 11.2.0.2 database after catalog upgrade to 11.2.0.4 (main question is 4th)

1.
We today have almost all databases running with Oracle 11.2.0.2.
Actually we have an RMAN database created (in 11.2.0.2) and a Catalog with user (called RMAN112)

2.
We are now installing new databases with version 11.2.0.4.

3.
What should we do in order to backup these new database ?


should we create a new user in the current RMAN databases ? (rman114 ?) even if those RMAN db's are running 11.2.0.2 ?
should we create a new RMAN database running 11.2.0.4, and new catalogs, dedicated for these 11.2.0.4 databases ?
should we upgrade the current catalog and how ?


I've just tested to register a new 11.2.0.4 database in the current catalog (11.2.0.2), it works, but then i had to do an "upgrade catalog" twice.
only problem : the backup of all the 11.2.0.2 databases now fail with errors like :

RMAN-00571: ===========================================================
RMAN-03002: failure of backup plus archivelog command at 11/21/2014 16:15:34
RMAN-06004: ORACLE error from recovery catalog database: ORA-04068: existing state of  packages has been discarded
ORA-04061: existing state of package "RMAN112.DBMS_RCVMAN" has been invalidated
ORA-04065: not executed, altered or dropped package "RMAN112.DBMS_RCVMAN"
ORA-06508: PL/SQL: could not find program unit being called: "RMAN112.DBMS_RCVMAN"
How do i fix that ? and what is the best practice ? 
after running a few "resync catalog;" it looks like i can backup a few 11.2.0.2 instances, but i don't really understand how it works..



thanks a lot

regards,
You should be able to backup an 11.2.0.2 database using RMAN with an RMAN repository that is set to 11.2.0.4. There seems to be some invalid objects in your RMAN repository schema. You may want to try compiling all of the invalid objects in your RMAN repository to see if they become valid. This probably has nothing to do with you backing up an 11.2.0.2 database with an 11.2.0.4 RMAN repository.