Hi Jim, yeah NURBS filleting is not really like a sub-d "auto smooth everything" type thing, particularly in juncture points where you've got several shapes coming together.

When you're going to get fillets that are curved in 2 opposite directions coming together at a juncture and then also maybe throw in another thing going off to the side at the same time, it's hard for it to figure out what to do automatically in that area where those pieces all come together.

The fillet engines in some of the much more fancier and expensive solid modeling systems like SolidWorks are more sophisticated at trying to deal with those areas than MoI's fillet engine though.

- Michael