I replaced my LMCE 8.10 server with a shiny new LMCE 10.04 server and built the rest of the network behind it. I then copied my handbraked .m4v files to the appropriate /home/public/data/videos/$DriveID folder and waited. Nothing ever populated on any of my orbiters.
If I go into the web admin / files and multimedia / media files sync, browse down the folder structure, I can see all of the files .m4v waiting to be added to the database. If I manually add one with TMDB attributes, it does show up in the orbiter for all to play, but the corresponding .id3 file is not created.
I renamed one of the handbraked .m4v to .mp4 (because they are essentially the same container) on the core and BAM, it showed up in the web admin as added, and it was displayed generically on the first orbiter I checked. Adding the TMDB attributes creates the corresponding .id3 file.
Renaming the files on the core from .m4v to .mp4 is an easy fix.
Hope this helps someone.