As Ido mentioned, you misunderstand how the report is being generated.
A shame you have no documentation, or even an idea of how the PDFs are being created. One thing you might try temporarily is to apply security to the folder that the report is being written to, and see if some program rears it's head with an error.
btw, did you try clicking the Enterprise icon from within Crystal Reports to see if there are any out there?
JohnOB: Since it's a scheduled process, then it is under the control of some other app, and they probably have no idea where.
Were you to try your theory on a CRS, CE or BOE server it would return files named similarly to GUIDS, doing you little good.
-k