Digital BW, The Print

Hi , I have a MIS CFS VM Hex set on my  Epson 1200 and am still 
in the experimenting phase. So far I have not been able to get 
consistent good results with it. Here are my two complaints :
1. The blacks are not consistent all the way through the gray 
scale step wedge. The darker shadow areas from about 50 
down to 12 are all very similar to each other in tonality  and then it 
suddenly jumps to a rich , deep black at the 0 step. So the blacks 
are there but not evenly distributed. In 'real' images the shadow 
areas look very flat , only the deepest' 0-value- shadows are nice 
and black. 
2. The inks seem to clog up very easily. It seems like EVERY 
time before I print I have to run several cleaning cycles. 
BTW, I am on a Mac and I am using Paul Roercks curves and 
workflow on Epson archival Matte. 
Any comments would be appreciated...