Do you use the glColorMaterial function ? If so, how ? If you don’t specify it, by default it will use color as ambient and diffuse components for lighting. But as you also seem to use material, then it is redundant. Choose one or another but not both. I suggest not to use color material.
arts, i’ve managed to “disable” diffuse with setting material R,G and B to 0 while light’s R,G and B components are all 1.
Concerning the GL_COLOR_MATERIAL - I don’t use glColorMaterial function, but I need this enabled so I can see the color of my object. Otherwise it is gray.
On the other hand I don’t use any material in a sense of texture or something.