Quote Originally Posted by Dead Moroz
The problem is that these bugs appears on places that have not even a pixel edited. And everything works great with default map_heights.tga.
You would be suprised what might have changed in just editing one side of the file.

Find the area in question.. eydropper it to verify that it is a valid greyscale range in rgb (all three numbers the same)

When in doubt.. zero to , 5, 5, 5 (I've found this height works well for transition from sea to coast)