hi, maybe that's a bug, what version are you using?
just try it:
1) Navigate to the $ORACLE_HOME/rdbms/admin of your recovery catalog
database.
2) Edit the file recover.bsq with an editor of your choice.
Change the following line:
< pieceCount_con number(2), -- backup set piece count (null)
to
> pieceCount_con number(5), -- backup set piece count (null)
3) Connect to your recovery catalog via the rman command line interface
and run the command :
RMAN> upgrade catalog
(you will be prompted to enter this command twice to confirm).
4) Rerun the 'list backup' command