If you haven't checked out hte error spec's

ORA-02002 error while writing to audit trail

Cause: The auditing facility is unable to write to the AUDIT_TRAIL table. If this error occurs, SQL statements that are currently being audited may also fail. This error will occur if the SYSTEM tablespace runs out of disk space.

Action: Add space to the SYSTEM tablespace or delete rows from the AUDIT_TRAIL table. If these operations fail or do not eliminate the problem, shut down and restart Oracle with auditing disabled. This is done by setting the initialization parameter AUDIT_TRAIL to FALSE.


It might have been that the auditing was on, then turned off by someone else besides you, due to the possible system files error(I'm not blaming anyone but ,although out of good intent, too many people tend to participate in many issues). Check out with the developers nad for all you know you might be able to run that job..)

HTH

Tarry