BTW, I've found the post I wrote about that subtitle timing bug. You can read it
here.
As you can see, it happens only with movies with several parts (multi-angle, multi-story or simply split for protection purpose), and furthermore it's not always the case. For example, the multi-angle Disney BD are not affected. Difficult to test in that conditions, but you can exclude all BDs made of only a single M2TS.