Digital BW, The Print

I hadn't used my 1280 CFS system for a while, and after many trials 
and tribulations have got it working again.  I decided to try to 
Tyler Boley curves for the first time.  Although they seem to be 
giving me smoother tones, I've run into a new problem--light banding, 
most visible in the mid-highlights, running in the direction of the 
print head.  It is just visible to the naked eye with the print held 
at a reasonable viewing distance (say 12 inches).  I'm printing on 
EAM and am using all the recommended settings ("heavyweight matt," 
1440 dpi, "no color adjustment," and "high speed" and "smooth edge" 
unchecked).  My first couple of prints seemed fine, but now 
the "banding" has ruined several prints in a row.

I assume this is a relatively common issue, but I've not run into it 
before.  Any suggestions?

Chris Patti