Help - level 0 backup failed due to RMAN 03009, ora-19540, ora-27038 failed to create file

Hello:

it is a normal scripts that we used for a while already; somehow it failed twice over this weekend (07/05/2010).  I adjusted once to change the backup format to be 'SCRMPRD_%T_%s_%p.bak' to avoid any conflicts with existing backups with extension of '*_bak'.  However, it doesn't work.

Backup commands:

RMAN> run {
2> allocate channel cd1 type disk;
3> allocate channel cd2 type disk;
4> set limit channel cd1 kbytes 2097150;
5> set limit channel cd2 kbytes 2097150;
6> sql "alter system checkpoint";
7> backup format '/orabackup2/path-to-destination/SCRMPRD_%T_%s_bak'
8> incremental level 0 as compressed backupset database;
9> sql "alter system switch logfile";
10> backup format