Changing textures on a Model messes up antialiasing? (XNA)

Question

Here is a code sample:

        blockModel = game.Content.Load<Model>("Models/Cubes/Cube"); //this is a .fbx file, made in blender

        absoluteBlockTransforms = new Matrix[blockModel.Bones.Count];
        blockModel.CopyAbsoluteBoneTransformsTo(absoluteBlockTransforms);

        /*
        foreach (ModelMesh mesh in blockModel.Meshes)
        {
            foreach (BasicEffect effect in mesh.Effects)
            {
                effect.Texture = game.Content.Load<Texture2D>("Textures/Cubes/CubeLayout"); //this is the texture it's already using, but copy-pasted into a different directory
            }
        }*/

This looks fine

Now if I uncomment the lines above, somehow everything gets screwed up?

Somehow just setting the Texture property messes something up, but I'm not sure what exactly (aside from the symptoms). Note that framerate doesn't actually change; the small difference is just a coincidence. Also, the multisampling property is set after this is called, so it's not an issue of it somehow changing the graphics property.

Answer 1

As was eluded to in the comments, the problem is that in the second half your textures are missing mipmaps.