RMAN ERROR - 06428

Hi,   I changed a db from archivelog to noarchivelog mode because there were a problem with archivelog (no free space in the recovery destination). When I solved this trouble, I set database to archivelog mode.
The problem comes when the backup utility try to execute de backup script.

RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of allocate command at 09/24/2013 14:55:54
RMAN-06428: recovery catalog is not installed

I'd tried to register database, and it answer the following:

RMAN> register database;

starting full resync of recovery catalog

RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03009: failure of register command on default channel at 09/25/2013 10:01:26