Using Greyscale gorilla HDR Studio to light a scene. It is a basic ticket with some text on it with a small animation wiping it on the screen.
Problem is that there are some black spots on the render. The first render was set to 'Animation' in the render settings and the result was these black spots on the render https://dl.dropbox.com/u/2003727/PIC_1.jpg
I thought I would then try a different render setting to see if I could get better results and get rid of these artefacts. I change the render settings to IR + QMC (Full Animation) the results where a lot better but there was still some problems with the render. https://dl.dropbox.com/u/2003727/PIC_2.jpg
I have increased the GI settings to Diffuse depth 5 and the Primary & Secondary to 100% and still getting the artefacts and disfigurement on the same place! Underneath the 'S' and on top of the 'or' in the pics. It should just not be happening.
Diffuse depth won't fix the problem -- it just tells the GI engine how many bounces to calculate. Five is probably overkill. Likewise, primary and secondary intensity just relate to brightness -- not quality.
You need to deal with the Sampling tab, which relates to the problem you're having. I suggest you read the GI section of the help docs as it's a fairly complex subject and the docs go into some detail.