archived logs, FRA not being purged as I expect

Hello, SuSE 11, x86-64, Oracle 11.2.0.3

log_archive_dest_1 = location=<path1>

log_archive_dest_2 = USE_DB_RECOVERY_FILE_DEST

rman "show all" includes:

CONFIGURE RETENTION POLICY TO RECOVERY WINDOW OF 7 DAYS;

rman backup statements regarding archived log backups: The following rman job is run nightly. 

sql "alter system archive log current";

backup

filesperset = 32

format='<CVJOBID>_%d_%U'

(archivelog  all   delete input );

show parameter recovery_file_dest reveals:

NAME                       TYPE        VALUE                                     

-------------------------- ----------- ------------------------------------------

db_recovery_file_dest      string      /u19/oracle/oradata/proddb/recovery_files

db_recovery_file_dest_size big integer 6G 

Total space used in recovery file destination as of now = 1.6G.