Duplicate Problems (RMAN is looking at the wrong backup)

Question

We are running into a problem when we try to duplicate our database. Here is the process we use to duplicate:
delete old backup files (we only use RMAN for cloning so we don't need them)
set prod db environment variables<run rman
connect target sys/####;
backup database;
exit;
set test db environment variables<shutdown test database, rename test db folder (in case we missed getting something important out) create a new folder for test db.
start test db (nomount)
rman
connect target sys/####@PROD
connect auxiliary sys/####@TEST
run
allocate auxiliary channel disk1 type disk;
duplicate target database to TEST;
we get this error:
channel disk1: reading from backup piece E:\RMAN\PROD\BKUP_PROD_610891176_1
ORA-19870: error reading backup piece E:\RMAN\PROD\BKUP_PROD_610891176_1
ORA-19505: failed to identify file "E:\RMAN\PROD\BKUP_PROD_610891176_1"
ORA-27041: unable to open file
OSD-04002: unable to open file
O/S-Error: (OS 2) The system cannot find the file specified.
failover to previous backup
The backup file RMAN is trying to read is the backup from our previous clone. How can I tell RMAN to look at the backup we just made?
I've run "list backup;" and the most recent backup is shown there. We've run into this problem a couple of times now, but not everytime. I can't find any rhyme or reason for why it works or fails but the process is the same sometimes we can just wait a half-hour or an hour and it works. Anyone have any ideas that could help?
BTW - We aren't using a recovery catalog.

Answer 1

http://dbataj.blogspot.com/2006/12/duplicating-database-with-recovery.html