ORA-01591: lock held by in-doubt distributed transaction

ORA-01591: lock held by in-doubt distributed transaction 
i restarted the server but of no use

solution:

SQL> select local_tran_id from dba_2pc_pending;

LOCAL_TRAN_ID

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

6.44.24689

SQL> rollback force '6.44.24689';

Rollback complete.

SQL> exec dbms_transaction.purge_lost_db_entry('6.44.24689');

PL/SQL procedure successfully completed.

SQL> select local_tran_id from dba_2pc_pending;

no rows selected

reference:

http://asktom.oracle.com/