QTR-Quadtone RIP

I'm using Curve Creator to create a curve for a new
paper using the 3MK inset on my R1800.

I've entered the data for my three inks and want to
save the curve and use it to print the test chart to
linearize the profile.

There's no Create Curve button on the interface.  I
assume it's been renamed to Show Curve.  Clicking it,
I'm asked whether I want to save my work, so I click
Yes.  The problem comes when I go to use the new curve
to print the 21-step test file:  there's no .quad file
in the appropriate QuadTone folder.

How does one create the .quad file?

Thanks in advance!

Ken Alexander