I can review the logs of the NAS-XSR Server and see if we see any errors that could be on our end. If you copy, create or modify a file with just another PC does this problem still exists (not using Retrospect) ? Any chance that you can contact Retrospect support for any clues to assist on this as well. If you are not using our client portion of our product it is very difficult to identify. Maybe something will show up in the logs. Please download logs, they are located in Web GUI, in status -> hardware -> Function: Logs then email logs to support@open-e.com.