[dustintheweb]

Yeah, what's weird is that all of "affected" files were specific to my movie folder and working perfectly just a few days ago. Which is why i'm thinking it was caused by some kind of rogue action from a file organizer app (either filebot, media center master, or Ember) - Any other MP4 anywhere else on my system works fine. So that, plus the fact that they've worked flawlessly for months, means handbreak probably isn't to blame.

I'll try your MKVmerge & binary editor ideas this morning and let you know how it goes. Thanks for the feed back on this.