cannot use system rollback segment for non-system tablespace 'TOOLS'

 Hi !!
I am using Oracle 11g on Redhat Linux-5.
I have duplicated my production database using RMAN on the same machine.
After successful completion, when I try to create a table it gives me error :

 cannot use system rollback segment for non-system tablespace 'TOOLS'

I have ran some checks as following:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
select segment_name, tablespace_name, initial_extent,status from dba_rollback_segs;

SEGMENT_NAME     TABLESPACE_NAME           INITIAL_EXTENT STATUS
------------------------------ -------------------------------------------  ----------------
SYSTEM                    SYSTEM                                57344 ONLINE
R01                            RBS                                   1048576 OFFLINE
R02                            RBS                                   1048576 OFFLINE
R03                            RBS                                   1048576 OFFLINE
R04                            RBS                                   1048576 OFFLINE

show parameter undo                                            

NAME                             TYPE     VALUE
------------------------------------ ----------- ------------------------------
undo_management            string      AUTO