To see newly copied media or other files on your DLink, Server (e.g. QNAP TS509), your PC/Mac and finally via the Playstation 3 player (PS3) on you TV do the following.
Generally newly copied files should be viewed properly the next day. But, if you need to immediately see your files after doing a copy then find how to do a 'refresh' on the server/Dlink. If you use the Media Player in Windows to interface PS3, open the Media Player program and watch the bottom right-corner for the information to clear or state finish. On opening the Media Player you will see "Retreival..." or "Updating..." flowing by as an indication that the data list is being updated now. If you have a PS3 opened you will need to reboot the unit AFTER the Media Player has completed its update; otherwise do not open the PS3 until the Media Player has completed. PS3 is dependant on a database file-list produced by the Media Player; this is what needs to be refreshed or updated.
For DLink login to your unit and find "Advanced > UPnP Server" and click the refresh button. This refreshes the DLink database file-list.
For any server: Investigate where the internal program permits a refresh. Some servers use TwonkyMedia, if so do this...
In TwonkyMedia, click the icon with the circle & wrench > click maintence > click rescan content directories.
If you are not using your server at the time, pressing "Rebuild" will close all activities and completely rebuild the whole database. With the Media Player refresh and the reboot of the PS3 you will definitely see any new media files just copied.