QTR-Quadtone RIP

First of all, Hello to everybody! I am new in this list and new to 
QTR and would like to start with a problem which has already been 
covered but not finally answered (to my knowledge - forgive me if I 
have missed a posting) :-)

I own an Epson R800 and have tried out QTR successfully obtaining the 
most usable b/w prints ever. However I have noticed (as some others 
before) that the image gets blurry, some kind of unsharp, the single 
dots become visible. Additionally at the end of a page I have some 
serious banding.

I printed in 1440x1440 mode (knowing that 2880 is recommended but in 
order to spare ink) with the cool curve and the "black" curve (which 
is, where I id get the banding).

Anybody has had similar experiences? Anybody has worked around this 
problem by defining a custom R800 curve?

Thanks to Roy for this wonderful piece of software.

Ignacio