Voronoi + offset = null

Hi,

I've notices, that when generating a voronoi diagram (resulting in 70 closed curves), and then connecting the output to an offset component, that offset component generates more curves, sometimes, up to 120 curves. Most of which are null.

This only happens when I have defined a containing box for my voronoi component. Otherwise, it doesn't.

How can I remove these Null items, since they cause problems later down the line when I want to extrude them. And why are they there?

Regards

- Björn