HeightMap Problem in my mesh

I dont know what is going on, my heightmap value strech in a custom mesh, but its fine with primitives from unity(Sorry bad english)![alt text][1] ![alt text][2] CUSTOM MESH and PRIMITIVE MESH!! as u can see, in my custom mesh heightmap goes to left and right, on primitive it goes correctly forward and backward. [1]: /storage/temp/80102-primitiveheightmap100.png [2]: /storage/temp/80103-custommeshheightmap100.png