When rendering an indoor sceene with Global Radiosity settngs I get leaking lights.
It seems I must delete the sun (directional light) to get rid of it, which is not a good idea since I need the sun for the landscape outside the window.

The attached image is only a preview render.

 Can't edit my post. Sorry.

I forgot to write if anyone have solutions for this?

Is it the same when you render at a higher preset? You may need to increase the photon map, this is possible only when using user render settings, then you can access the photon settings by clicking on edit next to the advanced effects quality box in the render options.

Maybe you could delete the sun and use local lighting for the landscape outside ?

I have noticed it also before, it is easy to replcicate by loading the default "Room radiosity" scene, delivered with vue. Then delete all everything execpt the room, also delete all lights and render

Then you ( or at least I ) will see a hugh light leak into the corner of the room.

It might helps solving the problem,

good luck.

Using only ambient lighting can produce a lot of leaking, unless conterbalanced by high GR settings. I'd recommend Chipp Walter's InteriorPak. Tough it was created for Vue6, many parameters are still accurate for V7.

 bruno, I now tested this setting with same results:
radiosity photon - 100.000
max photon trace level 50
Advanced effects quality - 100%

What I'm after is a sharp and crisp picture as possible with not too long render time, anything up to 12 hrs is acceptable (on a 3Ghz, 3Gb ram, single core machine) . This is because I have hundreds of images to render and they need to be done before I get too old.

Can the Global illumination , or any of the other settings, give a crisp and sharp picture? What settings should I have to accomplish that?

If you want indoor lighting, then you need GR. You must go much higher with the photon map, like 600000, but keep the trace level as default. Advanced effects quality at 100% is way too much. Keep it around 50%, and have about 500 gathering photons.
You may also need to adjust radiosity gain, and skydome lighting gain in the atmosphere editor. The right balance would be to have a nicely lit room, not too bright where the sun enters the room, because of light leaking(this is controlled by the skydome gain), and  a low contrast between the window and farther parts of the room (these parts need to be lit, they can't be completely in the shade, but they can't be as bright as the window area), this is controlled by the radiosity gain.

I would just like to add my 2 cents to what Bruno so rightfully said regarding the further away parts. To control the light in these parts, you can also play with the color of the radiosity gain. If you have it of a brighter color than the default black (even if only very slightly), the light will travel much deeper into the room.

 Still can't get rid of the leaking light.

Tried with R-photons set to 750.000
photon gathering to 500

In the atmosphere editor:
Dome light gain 1.0
Quiality boost +3
No xtra GR gain
Indirect skylighting ticked
Light & Amb balance 75%

And the 'Apply to all lights' ticked

Note: I am not worried about the other lights in the room at this stage, only the "leaking light".

I may have to ditch the sun after all. :(

What if you use lower skydome lighting gain, and a little radiosity gain? Lower skydome gain means less leaking, and adding GR gain will spread the light in the room.

 Tried that too but it is still visible.

I will have to render the windows separately and it is ok. Then I can add some animations to them too (not the windows but the landscape outside) which will be great for the game. So it turns out to be a good thing.

Thank you everybody for all the advice!  
/sends hugs to the guys/girls

The manual claims
"This problem occurs when the photon gathering radius is greater than the thickness of the walls"
and thus to correct the problem (in addition to what was already suggested) you could make the walls thicker or reduce the 'maximum gathering radius in the advanced effects.
The default of this radius seems to be 2m so if your walls are thinner, perhaps that's the solution.

 ArtPerl, you definitely have something there. :thumbupboth:
I did a quick partial render with my User settings and the leak is gone. Got some fungus dripping down the wall instead but that I can deal with.

Before I posted here I did a search in the manual for versions of leaking lights but nothing came up. Where was it mentioned?

Thanks a bunch!
/sends an xtra hug to ArtPerl

I'm so pleased!
I remembered reading it before, so I searched for 'leak' in the manual, it came up with only one hit:
It's in the trouble shooting section, I use 'complete' and in this manual its page 536. The sub section is "Bright Fringes Appear at Wall Base in Radiosity"

Thanks for the hug - really could use one today!

 Sorry seeing this so late. In anycase, yes you need to make sure your room is 'water tight' and has a wall thickness. Also, consider removing the ground plane if you see leaking around the baseboards and replace it with a regular plane. You may have to move it off the baseline of the floor as well. HTH.

Was going to suggest checking wall thickness as well. If it's just a plane, that might be your answer.