^ Well, when we were there, it looked as though they were focusing on three or four small, seperate sections of track. This was months after it was due to open (and the one in Beijing already had) by the way.
Then, when we did the one in Beijing it led us to think that it probably was a few dodgy areas of track, as a few parts of that were especially rough and jolty. Like, the turn into the brakes nearly broke my back.
I can't give you any evidence, and to be honest, I don't really care if you're not satisfied by what anyone is saying. I doubt they care, either.
Either way, there must have been SOMETHING wrong with it for it to open a year late, whereas a similar ride in the same country opened in time, and because they seemed to be doing extra work on a few sections of track, it's the only plausible explanation.