Digital BW, The Print

I just got going with my new MIS VM quadtone inks and EAM paper early 
this week.  My first attempt, on Monday, using a scanned negative (as 
a positive) and using Paul's Medium Warm curve for the Epson 1280 
worked great.  No banding, no solarization, great tonal range.  I'm 
really excited by the possibilites.

Since this first print, though, I've been having troubles.  This 
morning, I actually converted a color digital image and played with 
the channel mixers in doing so.  The image looks great on the 
monitor.  Lots of information and texture in all parts of the image.  
When I use the medium warm curve, though,  my bushes and background 
landscape areas are solarized and have significant loss of detail.  
Trying again, with the neutral curve, the bushes are now fine, but 
I've lost an incredible amount of detail on my building's brick 
wall.  Plus the smidge of landscape in the background still looks 
odd -- almost printed as flat tone.  (I've also had similar 
solarization problems with another scanned negative, though, where I 
printed it before and after adjusting the curves in selected areas.  
On this one as well, I was using the Medium Warm curve.)

Does anyone have any ideas about what my problem may be?  I'm using 
preload cartridges from MIS.  Is it possible that too much ink is 
coming out of some of the toner slots and not enough out of other?  I 
followed Paul's workflow steps very carefully, so I don't think I set 
something up wrong.  

Thanks in advance.

Bob