QTR-Quadtone RIP

hi,

I printed few prints with QTR and the first one was ok. But the second 
print printed so that few centimeters from the top were left out. I 
upgraded to the latest qtr and qtrgui (probably had them allready) but 
the symptoms persists. I printed the same image using epson driver and 
all went well.
After the print has stopped prematurely, printer wants anothe sheet of 
paper, but that paper passes through the printer without any printing, 
another sheet is wanted and so on. From the printer queue I have to 
manually delete the print jobs.
There's 160 GB of free disk space, so that's not likely to cause 
problems. Some usb problem? or what? I remeber having some sort of 
problems with epson driver, where the epson driver informed some 
communication error, but these were eliminated changing usb port. (it's 
not behind hub).

System winxp, 2GB ram.

thanks for any help

-matti