Terrain Textures Makes Dots

[LoveFest]

Painting is making dots for the layer with the alpha.
The dark dots is the layer with a dirt texture. I want it to show through the grass in some places, but it's making dots when I use the paint tool.

[LoveFest]

ffejnosliw from the UT forum at 3D Buzz.com gave me the answer. "The cause of this is not making the texture layers the same dimensions as the terrain heightmap. They must be the same."