Boolean Union, Creates Unwanted Copies

In beta, when I BooleanUnion, Rhino creates unwanted copys of un-boolean parts. I have to delete those parts before I continue. if this is not a bug, what setting do I need to change?

Thanks

Hi Davey - check the ‘DeleteInput=Yes/No’ ssetting at the command line.

-Pascal

Please excuse me for wasting your time. I found my mistake.