Error with RMAN cold backup

RMAN> CROSSCHECK BACKUP;

allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=49 devtype=DISK
allocated channel: ORA_DISK_2
channel ORA_DISK_2: sid=96 devtype=DISK
allocated channel: ORA_DISK_3
channel ORA_DISK_3: sid=37 devtype=DISK
allocated channel: ORA_DISK_4
channel ORA_DISK_4: sid=98 devtype=DISK
allocated channel: ORA_DISK_5
channel ORA_DISK_5: sid=74 devtype=DISK
crosschecked backup piece: found to be 'AVAILABLE'
backup piece handle=/orabackup/rman/control/c-4124556498-
20061027-00 recid=1997 stamp=604955892
RMAN-00571:
RMAN-00569:  ERROR MESSAGE STACK FOLLOWS
RMAN-00571:
RMAN-03009: failure of crosscheck command on 
ORA_DISK_1 channel at 11/11/2006 14:34:11
ORA-19608: /orabackup/rman/control/c-4124556498-
20061028-00 is not a backup piece

RMAN> RESTORE DATABASE VALIDATE;

Starting restore at 11-NOV-06

using channel ORA_DISK_1
using channel ORA_DISK_2
using channel ORA_DISK_3
using channel ORA_DISK_4
using channel ORA_DISK_5
channel ORA_DISK_1: starting validation of datafile backupset
channel ORA_DISK_2: starting validation of datafile backupset
channel ORA_DISK_3: starting validation of datafile backupset
channel ORA_DISK_4: starting validation of datafile backupset
channel ORA_DISK_5: starting validation of datafile backupset
RMAN-00571:
RMAN-00569:  ERROR MESSAGE STACK FOLLOWS
RMAN-00571:
RMAN-03002: failure of restore command at 
11/11/2006 14:35:14
ORA-19505: failed to identify file 
"/orabackup/rman/data/10NOV2006_8qi22lel_1_1_20061110_%S.bak"
ORA-27037: unable to obtain file status
SVR4 Error: 2: No such file or directory

1. Is my backup method valid?
2. Is that backup piece corrupt which is showing the error?
3. I am taking a cold backup daily.