QTR-Quadtone RIP

Hi All -

I just purchased an Epson 4800; this morning I downloaded QTR (have 
been hearing great things about it).

I used a grayscale .tif image, and accepted all the default settings 
in QTR.  I printed it on Epson Luster on the 4800 - it came out as a 
very dark mess (to put it kindly) No whites, extremely dark, etc.

So, I attempted to print the same image on my 2200 using Epson Matte 
and once again all default settings in QTR. The results were very 
similar, nearly identical (taking into account the differences in 
paper).

Are there some settings which I should start with, instead of the 
defaults?  I'm pretty sure that I'm doing everything correctly 
(although, maybe not :-> ) I'm just a little surprised that the 
default settings would be so far off.

Any help you could give to a QTR newbie would be greatly appreciated!

-E