There was also something about a wall collapsing at Tarxien.
I guess the Globigerina limestone, for all it's beauty, just isn't up to the job. The Coralline stuff seems to weather a lot better but I suppose in the long term, any form of limestone will break-down following constant exposure to acidic rain and temperature variation. It would be interesting to find out what the plans for the less popular sites are. Perhaps they are just going to let nature take its course.
(if you excuse the pun) there's no easy solution.