After looking into this problem and thinking it was a problem with the codex that my TWO Samsung TVs support I found it not to be the case.
It would play some file formats but not the one that I have been using for the last several years on my iTouch.
They would play on the TV if I punt them on a USB drive or played them with with my WD TV Live or WD TV Live Hub.
But they would not play when I used the DLNA feature to stream this MP4 format to my TWO Samsung TVs.
I had convinced my self that the problem was with the TV.
One of my NAS drives decided it wasn’t going to work any longer so I replaced it with a “Seagate - FreeAgent®: GoFlex™ Home 2TB External Ethernet Network Storage System”
Imagine my surprise when the file format that I was having trouble with would now play.
So now I’m thinking that it has to do with the DATA transfer rate of the NAS drives that I have including my WD TV Live Hub.
Has any one figured out how to get the WD TV Live Hub to Stream faster?