Rendering Particles In Passes

Does anybody know how to render particles in passes ?

Last night I had the problem with a particlerender. The I had tree types of particles, all of them with sprite shader, but tree different, animated imageclips. I needed 2 passes, one for the color and one for the depthfading. So I left the colorpass like it was, and cfreated a new empty pass, wtih a constant density volumeshader, fading to black. For the particlescloud I created a new partition. In this new partition I created an override for all particles, where I stored the "use rgb color" checkbox, so they didn't get the rgbcolorvalues from the clip, but from there original particle color, that was pure white.

This was the setup, and it worked fine.....

BUT only in the gui, previewing the stuff worked, the only strange thing was that if you switched from one pass to the other, you had to scrubb a little in the timeline, otherwise the rendersettings ( the override) for the particles would not update.

When it comes to render the complete stuff from the batch, only the last preview setting for the particle was renderd but for both passes. But even worse, if you had allready started one render, with correct pics, and then previewed the other pass from the gui, all following images from the rendering, second pass changed to the previewed settings.

Strange, isn't it.
Can somebody bring light to the dark.

CU Sanostol