Well, I had this problem when making hazar-kot aswell, but bypassed it by simply editing the satmap removing a lot of the edges and replacing it with the satout-texture.
Anyway, to explain the problem better, ingame (and in buldozer) the satmap isn't showing at the southern and eastern edges of the map, I guess pictures will explain better than I will:
(they're taken at the exact same spot and same time, just opened the map).
As you can see the satmap-texture starts appearing way too far north (I've marked the approximate position it appears with black dots).
Any idea what causes this? As you can see the satmap shows up fine on the ingame map (and in visitor 3), just not in the actual game and buldozer.
My sat_lco.png is 5120x5120 pixels if that helps. (and the terrain size is 5120x5120 metres)