Many thanks for the elaborate explanation, Laserdisc Master.

So it is as much hassle as I was afraid it would be .. Yeah, would have been too easy, I was already surprised that I could flawlessly sync the THX-certified (not that would mean anything, but it has in fact a bit more dynamic range than the BD mix) DVD-audio of Titanic to the 3D picture of the Blu-ray on the first try.

Is there any good reason for frames to be missing at all? I mean, don't they scan the source material frame by frame?

When you compare the video - which tool(s) do you use for that?

It would be great if there was a tool which would be able to compare two totally different video streams for its content frame by frame and detect any duplicates or missing frames.