Digital BW, The Print

I downloaded the Quadtone RIP for XP for the Epson 4000 yesterday, 
and installed it and ran it today. The prints produced on Epson 
Enhanced Matte paper looked excellent. I was anxious to do an AB 
comparison with my old method of making BW prints (ie., using the 
Epson Driver in Photoshop CS). Unfortunately, when I ran the same 
print, the results were terrible, much worse that prior to running 
Quadtone. The prints appear to be a duotone, using just the yellow 
and grey inks. I rechecked all my settings, tried several different 
prints all with the same result. I even tried shutting off the 
printer, and computer and rebooting without success. It's almost as 
though there was some internal switch that had been set in the 
printer, and which now cannot be reset. I'm using the latest 
firmware from Epson which is I0204AP. Can anyone offer advice as to 
what might be going wrong? Thanks in advance for any help you might 
provide.