I have heard reports that some of the Ricoh Printers are comming out of the factory with the Enhanced Locked Print feature turned on. If so, then ALL print jobs are expected to go into the locked print hold funtion and then be released by the user. Thru the units WEB inteface you may be able to turn this off. If you don't configure your PRINT job to use the LOCKED PRINT option ( in Job Log usually ) then the system could be set to ONLY allow locked print jobs, and those that are not configured properly will be discarded.
I would bet that you see the printers DATA light flash a bit before th ejob just disapears.