QTR-Quadtone RIP

Hi,

I have an Epson R230/R220 printer, MIS eboni ink and QTR. I am using http://www.cjcom.net/articles/digiprn3c.htm from CJ to try to print set up the printer using Clayton's 2KBO technique. 

I set up a curve as described in the article using the black and cyan ink positions and I have downloaded and configured CJ-2KBO-R200-Ordered.acv file. However, when I print an image where any areas are absolute black there is no ink coverage -- I just see white paper. When showing the curve I created the RH end of the curve has dropped to zero which is unlike CJ's example in the article.

(See https://picasaweb.google.com/drewt8/QTRTest for image of curve and my input/output images. but when I show the curve it looks different to the one in the article in that it (the curve) drops to zero at the right hand end. 

I have played with various parameters in the curve settings, I have printed the calibration chart without a problem which means that there is nothing wrong with a clogged head.

I am stumped... or am I stupid? Have I missed something obvious?

Thanks, 
Drew