how to emit colliding (rigid) softbody particles?

I’m stuck with the simple setup.

  1. created a cube as an instance
    1.1 enabled softbody: dumping 1.0, quad stiffs 1.0, pull/push 0.9
    1.2 enabled collisions: softbody dumping 1.0
  2. created a plane as a floor
    2.1 enabled collisions: softbody dumping 1.0

Now, when i reduplicate the instance, they fall pretty well.
But I want to emit them as particles, instead of duplicating alot of times.

  1. set up a plane as particle emitter
    render type: object;
    dupli object: the cube;
    size: 0.1
  2. scaled up the cube 10 times, because particle system cannot handle size 1.0

Now they fall like shit and do not collide with each other.

What do i miss?

Blend file: