I don't know whether this is a new bug/strange feature in TTDPatch, as I only noticed it recently, but it is very annoying:
The AI keeps raising and lowering the land all over a certain area! It doesn't seem to accomplish anything, but then again, nothing the AI does accomplishes anything... It keeps getting in the way of me building tracks, and I can't stop it other than by buying every and tile in the area (which, other than taking ages, I don't have enough money for)
An animated GIF of this happening can be found here
, but beware! It is very big. I reccomend at least a 256kbps connection.
P.S. Do you like my track layout