Digital BW, The Print

I am a UK photographer trying to produce fine art B&W prints using MIS 
Ultratone inks, Epson Archival Matte paper with an Epson Stylus Colour 
1160 printer. I have used a PC with Windows 98SE and Photoshop 5.02. 
Also an AppleMac G4 OSX Version 10.3.4 and Photoshop CS 8. I cannot 
produce any acceptable prints. I have followed the workflow detailed on 
the MIS website as far as possible, using the UT11 curves. All the 
results show tone separation with middle tones taking on a slightly 
blue hue. If I print without applying curves I get a continuous tone 
print, but very grainy. If I print from the browser, without going 
through Photoshop, I get a similar continuous tone grainy print. MIS 
Customer Services have been unable to offer a solution even though my 
systems must be quite common. Can anyone help please? David Herrod.