Digital BW, The Print

Hi guys -

I'm still experimenting and learning, but it seems to me that my
prints are missing a true, rich black - midtones and highlights are
really really nice (though contrast is a little low,) but blacks are
wimpy at best. Am I doing something wrong? 

System - 

1280
VM inks (in cartridges)
Mac
Photoshop 6
Paul's 1280 curves for mac, using his settings (Adobe RGB, PQIJ, Auto,
1440...)

Thanks :)

-Charley