QTR-Quadtone RIP

Hi,
I use an Epson 4000, Mac OSX 10.4.8
I am trying to print standard photo sizes using QTR, roll feed, cutter
on. Print is centred on oversize paper. The dimensions across the roll
are fine ie 8" for a 10x8" printed portrait but the other dimension is
only 9.85". The other .15" has cropped off the lead edge of the print.
The next print down is OK so why doesn't the lead edge print? I
normally print from PS2 and don't have this issue.
Regards
Graham