black or distorted textures after full render bake

I’ve tried all kinds of material UV etc settings in Blender 2.49.
But either get black or distorted textures.

What I’m trying to do is the trick of render-to-texture
after rendering with shadows.

I was able to full-render-bake a simple Plane with a Square over it.
That worked wonderfully. Shadow appeared correctly.

But after I subdivided the plane and made little hills,
then triangular artifacts appeared on the texture.
That is, baking worked when it was flat.