Digital BW, The Print

I have had my 1160 set up with MIS VM-QUAD inks since last Friday, and 
have made several prints. For the most part I think the prints look 
good, but I am not very happy with how the shadows look. They seem to 
have an unreal blotchy look to them.  I know this is not a very good 
description, but it's the best I can do. I thought that maybe I was 
trying to open up the shadows to much in Photoshop, so I went back to 
the original file and worked up the photos, paying close attention not 
to touch the shadows. It did not help much. I printed out a step test, 
which looks just, OK.  The step test does not have the nice smooth 
transition from the darker tones to white There is only a  slight 
change in density between 5% and about 30% and then the density jumps 
up.  It does the same thing again between 35 % and 50%, but between 50% 
and 100% the is a smooth transition.

Any help with this would be appreciated.

Steve