Hi Nick,

> The reason I brought this up is MoI is flipping the normals
> when they get 'seperated'. Has it always been like this and
> I never noticed?

No, it sounds like a bug. MoI does some work when you do a Separate so that all the pieces should retain the orientation of the original solid. So for instance if you do a Shell, Offset, or Extrude after that on the individual surfaces the results of those operations go towards the same direction as the solid pieces do.

But maybe something is not quite right with that for file saving, I'll take a look.

- Michael