RMAN Backup Errors

Hi ,

I scheduled backups for my database using RMAN. ( CRON jobs Using Scripts )
But frequently I am getting Following errors at end of the Backup, Can you please explain Solution clearly.

1). This is logfile Information what I am observing after cronjob completed

**************************************************************************************************** *********
piece handle=PRD364/cuml/gambfpcm_1_1/750249366 tag=PRD364_20110504095008_CUML comment=API Version 2.0,MMS Version 5.0.0.0
channel ch00: backup set complete, elapsed time: 00:01:55
Finished backup at 04-MAY-2011

Starting Control File and SPFILE Autobackup at 04-MAY-2011
piece handle=c-2140286471-20110504-00 comment=API Version 2.0,MMS Version 5.0.0.0
Finished Control File and SPFILE Autobackup at 04-MAY-2011
released channel: ch00
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03008: error while performing automatic resync of recovery catalog
RMAN-20033: control file sequence# too low

Recovery Manager complete.
'cuml' backup failed for instance 'prd364' at Wed May 4 11:01:52 2011
ERROR: (prd364) rman failed (256)

**************************************************************************************

2).this is for another database

****************************************************************************************************
channel ch00: backup set complete, elapsed time: 00:07:55
Finished backup at 04-MAY-2011

Starting Control File and SPFILE Autobackup at 04-MAY-2011
released channel: ch00
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03009: failure of Control File and SPFILE Autobackup command on ch00 channee
l at 05/04/2011 21:37:02
ORA-00230: operation disallowed: snapshot control file enqueue unavailable

Recovery Manager complete.
'incr' backup failed for instance 'dev823' at Wed May 4 21:38:26 2011
ERROR: (dev823) rman failed (256)
**************************************************************************************************** ****

What Could be the reason, what Is the solution ?
Same script is using for all databases , but I am getting this error for 4 databases Frequently.

I used 'RESYNC CATALOG ' , but still I am getting this error ?