Cycles Render Error with GPU?

Is anyone else getting this? If I Render with just CPU, there is no line. If I Render with GPU, I get this dark section at the top of my render with a distinct line/cut off. I was thinking maybe setting the size of the render sections might help, but does anyone have any advice on what to set them to? Maybe it’s something else?

It isn’t just a line. The entire upper part of the image appears to be getting treated with a different color transform. Can you share the blend file? If nothing can be found out, it might be worth reporting over at

Right… that is what I meant. Sorry if I didn’t word that right. Here is a better shot of it.
Q: What is the proper way to share a .blend file on these forms?

Drag and drop?

Ummm… yup, didn’t think of that. LOL

I think I’m going to put this on hold for now. There is definitely something goin on but I don’t know what. What’s strange is that it is not happening in any of my other .blend files. BUT - If I open a new file, and then append/import all the objects from this file, it starts doing it again. So - I can only think that one of the objects/materials is making the GPU go bonkers. I’m just going to have to keep messing with it until I find out what it is.

Not sure which step fixed this… but I deleted all unused data blocks, and I also had two mesh emitters occupying the same space, so I deleted one of them. Once I did that, the dark area disappeared.