Also check your app code, make sure you are closing any and all objects once the report is completed.
Do you know how large the report export is when it quits?
Do you have logging enabled in your app to see what is happening?
You can add crpe logging on that PC and see if it captures any more info, set the logging level to low first, it will generate a large file.
Search SCN, top right corner for the kbase article on how to enable logging.
Don