@hborre

Quote - The effect you are seeing is perfectly normal, that is how Gc should work.  You lights are still too bright in your second render with Gc, if you are looking to duplicate the image on the top.  Is there any material Gc present and did your render exactly the same as above, Gc off at render and Gc on for materials?

The scene contains no material gc.
The differenc between the post is only the Lights used.
In the first one BB's Full Body Lights was used. In the second on the pp2010 light set
Studio_RembrandtAO was used.
The rendersettings are saved in the .pzz and was not modified, except settig GC ON (2.2)
and OFF  for the two different render results.

@mackis3D
thank you for your advice  i will use it when i use vss again.
But the images i posted here are not based on VSS. There is no VSS Prop in the scene
(not yet)
I was using BBs Lights and the other LightSet just to show my problem.

Conclusions:
(Pls feel free to correct me, when something is wrong)
"My" lights are to bright, if i reduce them i well get result like the above pics.
(still  scepticism) but i will try hardly.

Hmm, so PP2010 offers us a Firefly render egine with linear rendering
plus the nice feature of Scene Wide GC (with easy turning on and off) to get
correct rendered images,
but they dont offer us light sets , considering the usage of the GC feature .

if i use one of pp2010's light sets and turn GC On with 2.2, i have to adjust the lights.
funny
is wish there would at last one setting, that considers GC ON.