The original disc has a pop-up, and it works! If I leave the original mpls, the disc starts and the main menu works also, but the main movie does not start at all (only the time counter shows, as if the movie is playing). Maybe its because I am also replacing an audio-track with a different coding (new: ac3 / old: lpcm)? But then again, I have edited the orignal mpls of the main movie in BDedit and changed the (expected) audio tracks in it to make it fit to the new audio in the new m2ts. Still, nothing plays...