This is what happens when you have the wrong scenerysheet.dds. I'm not sure of the precise name, scenerysheet01.dds perhaps. If you have the wrong one it will do that, or if you have more than one you will get the issue sometimes but maybe not all the time. Do a search in the main cfs3 folder for the texture name, and remove all but one. If that doesn't fix it then try each of the scenery sheets your search revealed in turn until it works. Make sure you only have one in your cfs3 folder, doesn't matter which sub folder it's in, cfs3 will find every one that is in the main folder or sub folders and choose one at random.