QTR-Quadtone RIP

I'm using QTR on a PC running XP. Files saved as greyscale tiffs as 
instructed and dragged to the print window. The results are terrible. Black 
and white photographs are printing very, very dark-wasting lots of ink 
(Eboni matt black and UT colour cartridges) in the process. I'm printing on 
Permajet Museum Classic for which there doesn't appear to be a profile so 
I've used the EEM profile (and tried one or two others as well with the 
same results).

Can anyone say what might be going wrong here? Using the limit and 
gamma adjustment tools help a little but prints are still far too dark. Other 
than sending a very light file to QTR, is there a solution?

Thanks,
Bruce