And THAT apparently did the trick …
The MKV file playing, when I made the log further up, was remuxed to m2ts, and now plays back nicely like before, but also doesn’t freeze up when seeking.
This is in 2D mode, however, as I’m still waiting for my new 3D projector, but I’m assuming it’ll work in 3D too. I’ll post on that later.
So right now it looks as if we’re dealing with some kind of MKV-related issue, am I correct?