Hello there!
I got not exactly the same problem, but some sort of it. I must say that my problem was that some old (original) maps from IT, like Waterfall, Desert, Oasis etc. didn't have their terrain highmaps and files "terrain.cfg", because all of them were in Default map folder, but Default had changed and all of those files were deleted. I had some facilitation, because I have old Impressive Title files and I just copied and added those files to game.
So, I think reinstalling or updating or something like this won't work anyway. I don't know why those important files weren't install.
I can add all those missing files here, if it could help you -
RAR:
http://www.mediafire.com/download/o3q74gb6dp2r2pn/terrains.rarZIP:
http://www.mediafire.com/download/j4ir4z43pri6vo3/terrains.zipYou just must copy the folders from file I uploaded and replace those with game folders
(your Last Moon folder>game>media>terrains)
~NaKomis