Lighting Problem

Recently I found a great tutorial about a virtual studio which can be used for designing or testing purposes:
Illumination Tutorial for Industrial/ Product/ Furniture Design

I carefully followed the tutorials. However, when I was done, the result scene did not look quite right.

Here is my rendered scene:

Maybe it seems to be totally Ok for you. However, it does not for me!

The big ball has this awful parasite light on the left and on the right. The small one has it too, but less visible.

How to get rid of this reflection? I doubt the real studio set-up produces such results.

The virtual studio set-up:

May it be that the round wall material is too reflective? But I completely turned off the reflectivity.
Here is the info about the scene.
Materials:

• Tea pot: Ceramic/Porcelain Ice White Autodesk Ceramic, High Gloss
• Big ball: Autodesk Hardwood with beechwood_gunstock.png image, Unfinished
• Small ball:  Autodesk Hardwood with Woods - Plastics.Finish Carpentry.Wood.Boards.png, Unfinished
• Board: Autodesk Hardwood with red_oak_classic_natural.png, Unfinished
• Scene round wall: Paint White, no glossiness, no reflectivity

Lights:

• Skylight: Multiplier 0.2, Map 100.0
• TPhotometricLight: Ray Traced Shadows, Emit Light from Rectangle 200x200 cm, Dimming 20% gives 300 lx)
• Two boxes with self illuminating material: Luminance 500

Rendering settings:

click to see the bigger screen shot

What am I doing wrong?

P.S.
The top view point shows the parasite reflection even better:

Here is the glossy finishing for comparison:

With glossiness the reflection looks totally Ok.