How to resolve "Resouce Busy" error generated by Coldfunsion function

Hello:

   I'm experiencing an intermittent error, e.g. ORA-00054: resource busy and acquire with NOWAIT, which apparently prevents users from exporting files simultaneously. Don't recall this being an issue in the past, however.  See attached Coldfusion error log file (resource_busy_error.txt).  Actual errors are on lines 353 - 355, and 369 - 371.  

   Also, note that the error points to a stored procedure called "ADDIDLIST" (Line 6), which is also attached (ADDIDLIST.txt).

  In addition, a CFC is attached (idlistgenerationDAO.cfc), which contains the functions (getIDList, and getExcludedIDList), both of which generate (and export) files at the same time.  It may be the cause of this error.  One file contains a mailing list of those eligible for a mailing (no restrictions), and the other lists those who were ineligible (restrictions existed).

   As I mentioned, it's intermittent, and may function fine for weeks without an error, but sometimes it may fail for a couple of days in a row.  I receive the error (via email) each time it occurs.

   I'd appreciate any assistance you can provide.

    Let me know if you need further clarification, or additional information.

   Thanks, and Regards,
resource_busy_error.txt
idListGenerationDAO.txt
ADDIDLIST.txt