@Sowthri: I have tried your .pdi file to export as a Microsoft Word document and reproduced the problem. I strongly suggest you contact our regular Technical Support service to report the problem. A ticket will be opened to address the problem. It would be escalated back to the development team.
Value symbols are initially displayed as ##### when the file is first openned and data has not been received yet. Instead of saving the file when the display openned, save the file on the first Display.DataUpdate event and then set a global flag that the display has been saved so that you can ignore additional DataUpdate events. Technically, this is not a bug because you are saving the display before it has data ...