RMAN> change backupset completed before 'sysdate-30' uncatalog;

RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of uncatalog command at 07/02/2008 12:55:34
RMAN-06122: CHANGE .. UNCATALOG not supported for BACKUPSET

Found this...

Oracle Error : RMAN-06122: CHANGE .. UNCATALOG not supported for BACKUPSET
Cause: The CHANGE BACKUPSET .. UNCATALOG command was entered. The UNCATALOG operation is not supported with backup set.
Action: Use CHANGE BACKUPSET .. DELETE instead.

Then did this:
RMAN> change backupset completed before 'sysdate-30' delete;
...
Do you really want to delete the above objects (enter YES or NO)? YES

But when I "list backupset completed before 'sysdate-30';" they're all still there... urgh

Any ideas?