More Sweep2 help

I am struggling with getting the sweep2 component to work correctly... Even though I have 2 profile curves, my definition (called basedefinition) results in one of the surface edges being distorted (out of plane).

As a test, I baked the curves from this definition and opened them as a new file and started a new (fresh and clean) definition (Sweep2_1), the resulting surface was quite satisfactory. But no matter how I flip the curves in my basedefinition, I cannot get a clean surface edge.

I would appreciate all help! Thank you.