m4v embedded images no longer showing

In a random attempt to try to solve other issues, I went from the release firmware to the latest for the WD TV Live Plus. With the release firmware, embedded images in m4v files were displayed as the thumbnail image. Since flashing to the latest release, they no longer show. I have see the meta data is still there in the file - its just not displaying.

I recently got an AppleTV. I use Handbrake to convert my DVDs to the preset for AppleTV then I use Meta X to properly tag the .m4v file. Works great when I import them to iTunes.

However…

When I add the same .m4v file to my Live Plus I don’t get the image either. If I switch the file extension to .mp4 the thumbnail shows perfectly though.