How can I prevent my part files from showing splines andcircles as faceted when I export a part to my cam prog as a .stepfile?

I am using Visualmill 6.0 and SW 2008 sp5. I tried bringing severalfile formats into Alibre and they all showed these facets as well,so it looks like some kind of setting in SW is causing these curvedfeatures to show up as faceted when exported.

This is a pain bc I am trying to machine a smooth spline in VM, butit keeps giving me these facets.

Thanks,

DougSolidworksImport export