Videos won't pause on DNLA network
 

I have successfully I stalled an Iomega DNLA network drive on my mac network. I have it plugged into my Apple Airport Express router. I am viewing my files via an LG BD660 BluRay media player. If I copy my files to an external hard drive and plug it into the USB port on the LG then I can play most formats of video file and get them to pause and to remember where they were if I leave them. However, if I copy the same files to my Network drive and access them on the media player several sorts of file will only play ie: no pausing or fast forwarding and no remembering playback position.
Anyone have any ideas why accessing the same files in different ways should have this effect?