Burned a new disc just now at 2.4x and now that one won't even start at all, not even if I do press quickly right before the demos come up in the start.
The first one where there should be some sections missing is the one running the best so far, but it will in due time show some errors too I guess.
The second one I burned at 4x seems to be the second best, although it gets "Disc could not be read" at some points.
Dang, this is annoying. ;P