Digital BW, The Print

In a previous post I mentioned the "stepped" transitions between areas 
of light and dark in some of the images I have tried printing.  

Here's a link to one of the previous messages:
http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint/message/7715
1

Some additional experimenting and learning has led me to believe that 
the transitions between dark and light in a general sense were only 
part of what I was seeing.  The real issue is between different 
densities of dark where the mixes of ink changes.  When I printed out 
the step wedges from Paul's site (on EEM using Pauls profile for EEM 
and Gamma 2.2 for the printer driver gamma setting) I noticed there 
are a couple of "transition" density levels where the different mixes 
of ink show up more obviously than others - between 70 & 80% and again 
between 80 and 90%.  

For 99% of images this isn't an issue but in images where the sky is 
very dark and therefore has large areas where those transitions 
mentioned above occur it becomes visible - almost like a line across 
the page wherever those transitions occur.  (It's much easier to see 
the transitions on wide areas where it occurs - I didn't notice it 
when I was printing test strips (1"x8") from the center of the image 
below.  This result doesn't occur with BO printing because it's all 
the same ink.    

Here is an example:
http://www.flickr.com/photos/brianechapman/75838437/

Does anyone have any suggestions to reduce the effect?  

Sorry for the long post, I just wanted to make sure I gave enough info!

Thanks!!

Brian 
http://www.brianchapmanphotography.com