Helix * Sweep => very slow Moi3d

 From:  ggagnon
4045.1 
Hi,
I want to make a screw so I sweep a three sided poligon and use an helix for rail. It works fine except any further commands take a long time to execute.
That does not affect other applications that are running on the computer at the same time, only Moi3D is affected.
Why is that and what can i do to prevent it?
Thanks,
Gaston