Intel shading issue

Hi,

I have run into issues on the intel platform with an interesting shading phenomenon. This is pretty basic, but I have no clue as to what is going on… the same code was used to render these two scenes consisting of just some triangles and very simple single lightsource close to the viewer…

http://www.lewlight.com/ShadingProblem.jpg

Any clues at all?

Stock answer:
Have you checked for OpenGL errors (eg. calling glGetError() somewhere during the frame or using GLIntercept?)

Check your normals, look for uninitialized things in lighting.