Position Object - Particle per Vertex

I'm in desperate need of a script that can help me out.

I have 27 cubes in my scene. And a Particle Emitter wich emmits 27 particles. When i add a position object to the event and lock on emitter. The particles are not evenly distributed on every Cube. Some Cubes don't have a particle on them and some Cubes have multiple particles. How can I distribute it evenly?

It looks like the particles are spreaded randomly over the vertices.

I hope someone has a simple script for this.

You can download the max file here:
http://www.maartennauw.com/CubeSetup.max

Thank you very much!

For more info about me:
www.classifiedfx.nl