Weird explain plan

We have upgraded from Oracle 8 to Oracle 9.2.0.6.

I am getting a bitmap conversion. We do not have a single bitmap index in our system. Is this possible ? The query is now slow as opposed to before. We are using an ORDERED hint in the query. Grateful for any help. Thanks

SELECT STATEMENT Optimizer MODE=CHOOSE 1 153987

  SORT ORDER BY		1  	155  	153987
    NESTED LOOPS		1  	155  	153985
      NESTED LOOPS		1  	145  	153984
        NESTED LOOPS		1  	133  	153983
          NESTED LOOPS		1  	120  	153982
            NESTED LOOPS		1  	71  	153981
              MERGE JOIN CARTESIAN		20 M	1G	46641

                VIEW	SYS.VW_SQ_1	23 K	382 K	599

                  SORT GROUP BY		23 K	382 K	599

                    TABLE ACCESS FULL	AD251LCL.trans_log_ip	80 K	1
M	129
                BUFFER SORT		910  	31 K	46641

                  TABLE ACCESS BY INDEX
ROWID	AD251LCL.insured_person	910  	31 K	2
                    INDEX RANGE SCAN	AD251LCL.IX_PKY_2001009	208  	 	1

              TABLE ACCESS BY INDEX ROWID	AD251LCL.trans_log_ip	1  	19
	153981
                BITMAP CONVERSION TO ROWIDS

                  BITMAP AND
                    BITMAP CONVERSION FROM ROWIDS

                      INDEX RANGE SCAN	AD251LCL.IX_PKY_2001021	1

                    BITMAP CONVERSION FROM ROWIDS

                      INDEX RANGE
SCAN	AD251LCL.IX_FGN_2000999_2002266	1
            TABLE ACCESS BY INDEX ROWID	AD251LCL.party	1  	49  	1

              INDEX UNIQUE SCAN	AD251LCL.IX_PKY_2001044	1

          TABLE ACCESS BY INDEX ROWID	AD251LCL.staff_group	1  	13  	1

            INDEX UNIQUE SCAN	AD251LCL.IX_PKY_2001208	1

        TABLE ACCESS BY INDEX ROWID	AD251LCL.employer	1  	12  	1

          INDEX UNIQUE SCAN	AD251LCL.IX_PKY_2001030	1

      TABLE ACCESS BY INDEX ROWID	AD251LCL.party	1  	10  	1
            	 
        INDEX UNIQUE SCAN	AD251LCL.IX_PKY_2001044	1