RS700 Readyshare photos

I just installed a nighthawk RS700 router and updated to the newest firmware. I installed a thumbdrive in the USB port that has folders with photos and music. I have no problem mapping to the network location of the drive, and I'm not totally sure if my problem is related to the router or the display TV I use to display the pictures from the drive, but to begin with, the router I replaced had a similar media server and it displayed thumbnails of the pictures readily on my Samsung TV when I clicked on a folder. With this new router, I see the folders, open them, and see placeholders but no thumbnail pictures. These are the same pictures, same thumb drive, same TV. Only difference is the router. Is there something I can do to get the thumbnails created? What could be the problem?