EMD_MAINTENANCE.EXECUTE_EM_DBMS_JOB_PROCS generating trace files in bdump

 I can't seem to find any information on this subject that will help me.  The job EMD_MAINTENANCE.EXECUTE_EM_DBMS_JOB_PROCS(); is generating a lot of trace files in the bdump directory.  Some of the files are very large and they are consuming a lot of disk space.  In reading the trace files, I can't understand why these files are being created ( there's no obvious error message ).  I know this job runs under sysman and is used for Enterprise Manager control.  If anyone could shed some light as to why these files are being created and how I can prevent it, I