QTR-Quadtone RIP

I'm inexperienced using this program and am puzzled why prints look 
flat and "blacks" are typically gray with less contrast than I'd expect.

I usually punch up saturation and/or contrast in the RGB original and 
the black/white conversion looks fine on my CRT monitor. Color prints 
closely match the monitor but not so with black/white. I know I could 
further darken the image in PSCS3 but it would be strictly a guess as 
to the printed result. The monitor is calibrated and I have no trouble 
with color printing.

I use an Epson 2200 and matte paper.

Thanks for your help