Drafted Surface Problem With Mold/Casting Application

[anyoldname]

I'm using the Tool Design Set/Mold/Casting tool to add draft to piece of geometry that is too complex to draft using the basic draft functions (the surfaces are all curved and run at various angles relative to the pull direction).

The Draft Line function creates a curve where the flat drafted surface would be tangent to the curved surface, taking into account the draft angle and pull direction. However, when I add the drafted surface using the Tangent Draft function (which should create the drafted surface by using the draft line as its edge with the drafted surface being tangential to the base surface), the actual drafted surface comes in at half the angle specified by in the Draft Line. I can easily adjust the value accordingly but the join between the drafted surface and the base surface has a sharp edge.

Any ideas why this happens or how it can be worked around?

(I'm running WF2)

Thanks, Andy