Digital BW, The Print

I'm using an Epson 9600 with UltraChrome inks (Matte black), Somerset 
Velvet for Epson, and ColorBurst RIP (PC version).  I custom-built a 
profile (DTP-41 with UV filter and Monaco Profiler Pro) to be used 
specifically for black and white images, and have had great results.  
The problem is that I have some images I need to print for a customer 
that have a smooth gradient - basically a heavy dodge on the subject 
matter to create a halo effect - that show some "breaks" in the 
transitions.  When I print a gradient test image (created in 
Photoshop) I can see them, albeit they are very slight, meaning it's 
not an artifact from adjusting the file.  I've tried different 
resolutions and screening algorhythms (lower quality is slightly 
better, but still not perfect) to try and improve things, but I can't 
completely get rid of it.  I've printed the test with no profile 
applied, and it seems to be there in the linearization as well.  I 
even tried some tests with no linearization or profile, and I get the 
same problem.  Has anyone been able to print a super-smooth, perfect 
tonal gradient with this (or any) inkjet printer?  Or am I always 
going to have some slight rough spots?  Every other type of black and 
white image I print looks beautiful... it's just these damned 
gradients without any texture that give me fits.  

Sarah Smith