Catalog resync issue, Unique constaints violated

Hi Experts..

Got some issue in catalog..require help desperately..

Oracle : 11gR2

Here is a detail of error.

starting full resync of recovery catalog

RMAN-00571: ===========================================================

RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============

RMAN-00571: ===========================================================

RMAN-03009: failure of resync command on default channel at 11/26/2013 18:01:34

ORA-01403: no data found

ORA-00001: unique constraint (DNKF_GRIP.BRL_U1) violated

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Regards,