Sunshine, you need to do a couple of things:
First in the 'Page Setup', bottom of the L-panel in the Print module, select the correct paper size that you are feeding the printer.
Second, you need to alter the cell size - this is done in the 'Layout' sub panel that is part of the R-panel in the Print module.
If you are doing these things then you need to provide a step-by-step description of what you are doing.
Ultimately though the fix will be very easy - if we know where you are going wrong.
Thanks for the replies
Just in case I'll put this info up here as well.
I have set the paper size and cell size.
I've just printed the image perfectly on 11x17 paper - it's the 13x19 paper that seems to be the problem for some reason.
Here is the requested screen shots.