SpringJoints going wild: Affecting other prefabed Objects/SpringJoints

I’ve got a SpringJoint (without a connected body) applied to a gameobject. This gameobject is together with other gameobjects in a prefab.
Everything is working like expected except when I use multiple instances of that prefab:
The other objects get affected if oh SpringJoin gets a force.
You can have a look at it here:

http://www.schwarmgeist.de/unitytest/springjoint/

I’m using the Orthello-2D-Framework if that matters. Any idea ?

Thanks a lot
Martin

I think I found the mistace:
One script within the prefab somehow found it’s way copied to the parent gamobject holding the spring-gameobjects. I’ve got no idea how it came there, but it seemed that it controlled all three springs.