Strange Path Shift Bug?

I have a strange thing happen with the Path Shift component.

It shifts a list of polylines which are then used to create Boundary Surfaces.

Before the PShift component, all the polylines create Untrimmed Boundary surfaces but after the data has gone through the PShift component some of the surfaces are trimmed and appear to be zero surface area.

Is this another reason to upgrade to Martyn V2.0 or is this a bug?

PLine to Boundary Surf:

PLine through PShift to Boundary Surf: