Problems with 11gR2 HASH partitioning

Hi all, I've an issue with two HASH partitioned tables when joined amongst themselves (11204). Whosoever did partitioning didn't follow 2^N logic and the details are

  1  select partition_name, tablespace_name,num_rows,blocks
  2  from dba_tab_partitions
  3  where TABLE_OWNER='USER_PROD'
  4* AND TABLE_NAME='DEPENDENCY'

PARTITION_NAME                 TABLESPACE_NAME                  NUM_ROWS     BLOCKS
------------------------------ ------------------------------ ---------- ----------
SYS_P6463                      CUPD1U_BIG_TS01                         0          0
SYS_P6464                      CUPD1U_BIG_TS02                 922346296    8788624
SYS_P6465                      CUPD1U_BIG_TS03                         0          0
SYS_P6466                      CUPD1U_BIG_TS04                         0          0
SYS_P6467                      CUPD1U_BIG_TS05                   1010903       7054

  1  select partition_name, tablespace_name,num_rows,blocks
  2  from dba_tab_partitions
  3  where TABLE_OWNER='USER_PROD'