EntityShininess - Seamlessness?

I have a textured sphere that looks fine with EntityShininess 0, but when i add sine it makes the seam apparent...



How can I avoid that?

I think it's because your mesh is too low poly to have enough detail for shininess. Try it on a higher poly sphere.

I tried it with 100 segments and it doesn't look any better.

Hmmm, that doesn't look like a seem of the sphere mesh. Looks like something is cutting into it. I assume you created your mesh in blitz via the createsphere() command?