Digital BW, The Print

Paul and others --

Some questions and comparisons from a novice:

I'm just starting to experiement with my new Epson 
1160/VM/Mac/Photoshop 5 setup. I've made a few test prints, 
printed a couple of step wedges and Tyler's Zees, and so far I've 
found that there are "inkjet dots" (for lack of a better term) 
apparent in my prints at the higher end of the wedge, while the 
test (staircase) print sent me by the Piezo folks have none 
visible.

Using the neutral-cool (nc4) VM curve, I'm getting visible dots at 
20% and above on the 21stepwide8bit.jpg scale and 15% and 
higher on the 21stepNew.jpg scale. I'm printing on Epson 
Archival Matte paper, and I've tried turning the high-speed setting 
off in the Epson printer driver. Also, I've tried setting the gamma 
to 2.2 instead of 1.8 in the sRGB settings in Photoshop.

The Piezo sample, in contrast, which is printed on Somerset 
Enhanced paper, does not have inkjet dots visible in the brighter 
range. It was printed on an Epson 3000, however. (Also, there is 
some dottiness in the middle part of the wedge, but I think that 
looks more like it could be because of absorption problems.)

So my question is this, ultimately: What can I do differently so 
that my prints are "dotless" in the brighter areas?

I've also noticed (on the Tyler's Zees image) that I am getting far, 
far less tonal separation on paper than I am on screen. (Also a 
lot of visible dots in the bottom row, especially the bottom right 
square.)

I'd appreciate any help.

Thanks,
Peter