Re: Light Issue
It looks like this could be an issue with your shadow-casting and non-shadow-casting lights occupying the *exact* same space.
My apologies - I realize that this is exactly what I told you to do in the earlier post. I initially tested the above solution using mental ray, which didn't have these shadow artifacts that you are experiencing. Looking at your render, though, it looks like you might be rendering in V-Ray, and when I tested this setup in V-Ray, I was indeed able to reproduce the shadow artifacts that you are getting on the side of your cylinder.
To resolve this problem, try taking the shadow-casting version of your duplicated light, and move it very slightly in front of the non-shadow-casting light.
It seems that when the 2 lights were in the *exact* same spot, the rectangular light plane from the non-shadow-casting light may have been interfering with the shadows from the shadow-casting light, resulting in the shadow artifacts.
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