I just replied to your thread on the SprutCAM forum with what may be a more successful resolution to the faceting issue. If that site is down (all too common), here is a link to the STC file I created for your part:
http://member.newsguy.com/~mphenry/T...Groove-MPH.stc
To create the file, I imported your IGS file into Alibre and then exported that as a renamed IGES file and then manually imported the re-named file into SprutCAM.
Mike