Digital BW, The Print

Hi,

i installed a CFS system with MIS VM inks on my 1160 sometime last 
week. Followed all the instructions (purging, etc) till i got good 
consistent nozzle checks. Since then i've printed out about 80 A4 
sheets of epson archival matte paper using Paul Roark's curves. I 
notice some microbanding in certain areas of the image whenever i use 
the warm curve. Its only noticable if i look very closely at the 
print under certain lighting. I don't seem to get it if i use the 
other 3 curves. The nozzle checks are fine, i did try doing a few 
cleaning cycles and did a printing head alignment. Any ideas on how i 
could get rid of the microbanding? 

Not too sure if it has anything to do with my workflow which is 
roughly as follows:-
1) scan b&w negative using minolta scan dual III (at 48bit RGB, 2820 
fixed dpi, RGB working space)
2) Image adjusted in PS7 in 16bit mode, mainly
   - clean up image (dust, etc) using the healing brush
   - curves for contrast adjustment
   - bits of dodging and burning using curves and the history brush
   - edge USM if needed
3) When i am ready to print, i will 
   - convert the image to greyscale then back to RGB (sRGB working 
space)
   - assign whichever Roark curve that i want
   - Print with preview
     - set the size of the output image (normally 10 inches wide for 
landscape, 10 inches high for portrait)
   - In the printer dialog preferences
     - Paper set to Matte HW
     - High Speed Off
     - 1440 dpi
     - Center Image
     - color controls --> auto
   - Print

I'm still very new at this so any help is appreciated. Also are there 
any other curves available for the MIS VM inkset on the 1160 that i 
could try?

Thanks

Derrick