Radiosity render enabled destroys my displacement map

Hy guys!
I’m new to Blender world and maybe my question has an easy explanation, but I’ve encountered a strange behavior of the internal rendering engine in my test.

I’ve a scene with a UVSphere, some lights and a ICOSphere simulating G.I. Of course I have a material also, and I’ve applied that to my UVSphere.
The material is a simple simulation of a tree bark, it include some textures, 2 of those textures are mapped to Displace my UVSphere, to render a sort of crack in my surface.

And now the problem!

1 - When I render using the spots only as a source of lights and disabling Radiosity for my scene I obtain this result:

http://img80.imageshack.us/img80/5787/noradmm6.jpg

2 - When I render using the spots and the G.I. ICOSphere as a source of lights and enabling Radiosity that’s what come up on my screen:

http://img80.imageshack.us/img80/8523/radkc3.jpg

It seems like the Radiosity function can change the amount of my displacement mapped textures by its own decision…
How explain that? The Material is the same, the Textures are the same so the Camera, the Lights and the whole Scene are.
Who is the responsible to those differences? How can I achieve a single result for Rad and No Rad rendering?

Hm, that is quite odd. And probably people much smarter than I on this forum can answer this for you. However, if I had to guess, I would say it has something to do with the material’s texture map input. What setting are you using for Map Input? You might try UV mapping the thing and using the UV input. If you’re already using that just play around with different ones, maybe that will give some insight to the culprit :confused:

All textures in my material (6 textures) are Orco mapped, Sphere. The only differences are in X, Y, Z settings with differents values for stretch and resize in each of those. Some of the textures are Map To Color, some to Normal, some to Warp and Displace. The textures with Displace mapping seem to be ignored by the Radiosity rendering.
I’ve tried to use UV mapping but the result is the same.

Here are some example of the tree I’d want to apply the material to. I’ve added the Edge rendering for an immediate spotting of the issue.

In this image the Radiosity render is disabled and all is fine:

http://img237.imageshack.us/img237/8084/noradfl9.png

This image otherwise, shows the result with Radiosity rendere enabled and here come the issue:

http://img358.imageshack.us/img358/1695/radre7.png

As you can see the Radiosity render destroy every Displace Map I’d like to apply to my tree turning the bark surface in a smooth one pretty unrealistic.

Some hints?

Any ideas?