Digital BW, The Print

I have just purchased MIS ultratone inks and converted my 2200. I 
have run some test 21 step wedge prints and some images. I noticed 
the grain was barely visible in the step wedge print and in the 
really light even tones in the image print, the dots are readily 
visible and in fact are about .5 mm. apart.  As near as I can  tell 
they are all black and no greys. I tried setting up the printer to 
do sepia only and it came out the same warm black colour, slightly 
lighter though than the previous print which was supposed to be warm 
black. Clearly there is no sepia on this print at all. Nozzles are 
fine. It's as if somehow it is printing black only instead of colour 
(shades). I followed the quadtone and 2200 help files exactly. What 
obvious step am I missing?

Thanks

George