Digital BW, The Print

I have been trying to print 4 a5 images on an A3 sheet as a test strip
to compare different QTR settings. 

I made 4 different tiff files with the image in each quadrant of the
page then between each print I reload the paper and alter the QTR
settings in QTR gui. 

The problem is that although the file with the image in the top left
quadrant prints ok, where the image is on the top left, the printer
only outputs the top 1/3 of the A5 part of the image. 

This is quite a repeatable problem. I wonder if its a bug in QTRip in
how it decides when printing is finished. 

Has anyone come across this problem, maybe when printing images with
large areas of white border on the left? 

I'm using QTRGui, but looking at the debug output, it looks like the
right parameters are being sent to QTRip.