I am working on getting try dynamic lighting rigged up in our engine, and I am getting a wierd issue. I thought I had covered all the basis (proper light model settings, proper GL_LIGHT0 settings, GL_LIGHTING and GL_LIGHT0 are enabled, proper material settings, normals are being passed), but I guess I haven't. The wierdest part is, anything drawn during the alpha blending step of a render pass (i.e. those objects drawn with alpha blending enabled) draw correctly. To see the problem, look at the screenshot here: http://www.wildfiregames.com/~matthew/lightprob.jpg Anyone have any idea what causes this?

Any ideas at all? :)

Perhaps your normals are flipped. One way to test this out would be to invert the light vector ( assuming a directional light )...