bemfarmer, I used a "through points" curve. Its probably not exactly a plot of the sine() function. I used it because it easier to place and achieve an even curvature(what what I had in mind when I said "accurate").

Michael: The way you repaired the problem(join then delete the point) is completely new to me. Until now I have been rebuilding curves or scaling points so they are co-linear <- how dopy!!
Its interesting how habits and assumptions from other software persist.

Thx as always,
Ambimind